JP2016038490A - Display panel, display module, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an all-weather display panel that is flexible and is low in power consumption.SOLUTION: A flexible display panel has a first display element 103 and a second display element 107, the first display element 103 comprises a first portion overlapping the second display element 107, the first portion is capable of emitting light to the second display element 107 side, and the second display element 107 has a portion with a variable light transmittance.SELECTED DRAWING: Figure 2

Description

One embodiment of the present invention relates to a display panel, a display module, a display device, and an electronic device. Another embodiment of the present invention relates to a method for driving a display device.

Note that one embodiment of the present invention is not limited to the above technical field. One embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. One aspect of the present invention relates to a process, machine, manufacturer, or composition (composition of matter). Therefore, a technical field of one embodiment of the present invention disclosed in this specification more specifically includes a semiconductor device, a display device, a light-emitting device, a power storage device, a memory device, an electronic device, a lighting device, an input device (eg, a touch device) Sensors, etc.), output devices, input / output devices (eg, touch panels, etc.), driving methods thereof, or manufacturing methods thereof can be given as examples.

In recent years, development of a flexible device in which a functional element such as a semiconductor element, a display element, or a light-emitting element is provided over a flexible substrate (hereinafter also referred to as a flexible substrate) has been advanced. Typical examples of the flexible device include various semiconductor circuits having semiconductor elements such as transistors in addition to lighting devices and image display devices.

The display device is expected to be applied to various uses. As a display device, for example, a light emitting device having a light emitting element and a liquid crystal display device having a liquid crystal element have been developed.

A light-emitting element (also referred to as an EL element) using electroluminescence (EL) can be driven by using a DC low-voltage power source that is easy to thin and light, can respond to an input signal at high speed. Etc.

For example, Patent Document 1 discloses a flexible active matrix light-emitting device including a transistor or an organic EL element as a switching element on a film substrate.

Patent Document 2 uses a polymer dispersed liquid crystal (also referred to as PDLC (Polymer Dispersed Liquid Crystal), polymer dispersed liquid crystal, or polymer dispersed liquid crystal) that performs display using light scattering by liquid crystal. A liquid crystal display device is disclosed. Since a liquid crystal display device using a polymer-dispersed liquid crystal does not require a polarizing plate or an alignment film, cost can be reduced and power consumption can be reduced.

JP 2003-174153 A JP 2012-3250 A

An object of one embodiment of the present invention is to provide a display panel or a display device with low power consumption. Another object of one embodiment of the present invention is to provide an all-weather display panel or display device. Another object of one embodiment of the present invention is to provide a highly convenient display panel or display device. Another object of one embodiment of the present invention is to provide a display panel or a display device with high visibility regardless of ambient brightness. Another object of one embodiment of the present invention is to provide a flexible display panel or display device. Another object of one embodiment of the present invention is to reduce the thickness or weight of a display panel or a display device.

Another object of one embodiment of the present invention is to provide a novel display panel, a display device, an input / output device, an electronic device, or the like.

Note that the description of these problems does not disturb the existence of other problems. Note that one embodiment of the present invention does not have to solve all of these problems. Issues other than these will be apparent from the description of the specification, drawings, claims, etc., and other issues can be extracted from the descriptions of the specification, drawings, claims, etc. It is.

One embodiment of the present invention is a flexible display panel including a first display element and a second display element. The first display element includes a first display element and a second display element. The first display element has a first part that overlaps the first display element, and the first part of the first display element has a function of emitting light to the second display element side. Is a display panel having a portion with variable light transmittance.

Another embodiment of the present invention is a display panel having flexibility, which includes a first substrate, a second substrate, a first adhesive layer, a first display element, and a second display element. The adhesive layer is located between the first substrate and the second substrate, the first display element is located between the first substrate and the adhesive layer, and the second display element is Located between the second substrate and the adhesive layer, the first display element includes a first electrode, a layer containing a light-emitting organic compound (hereinafter referred to as an EL layer), and a second electrode. The EL layer is located between the first electrode and the second electrode, and the second display element includes a third electrode, a layer containing liquid crystal, and a fourth electrode, The including layer is located between the third electrode and the fourth electrode, and the first display element has a first portion in which the first display element and the second display element overlap each other. , First of the first display element Min has a function capable of emitting light in the second display element side, the second display device, the light transmittance has a portion which is variable, it is a display panel.

In each of the above structures, the first electrode is located between the first substrate and the second electrode, and the first electrode has a function of reflecting visible light, and the second electrode Has a function of transmitting visible light, the third electrode has a function of transmitting visible light, and the fourth electrode has a function of transmitting visible light. It is preferable to have.

In each of the above structures, the first adhesive layer includes the second adhesive layer, the third adhesive layer, the first insulating layer, the second insulating layer, the first transistor, and the second transistor. The second adhesive layer is located between the first substrate and the first insulating layer, and the second insulating layer is located between the first substrate and the first display element. And the second display element, the third adhesive layer is located between the second substrate and the second insulating layer, and the first transistor and the first electrode are electrically The second transistor and the fourth electrode are preferably connected electrically.

In each of the above structures, the first display element has a colored layer and a light shielding layer, the first portion has a portion that overlaps with the colored layer, and the second transistor has a portion that overlaps with the light shielding layer, The colored layer is located between the second substrate and the fourth electrode, and the colored layer and the light shielding layer preferably have a portion provided on the same plane.

In each of the above structures, the layer containing liquid crystal preferably contains polymer dispersed liquid crystal or polymer network type liquid crystal.

Another embodiment of the present invention is a display module in which a connector such as an FPC (Flexible Printed Circuit) or a TCP (Tape Carrier Package) is attached to a display panel to which each of the above structures is applied. Another embodiment of the present invention is a display module in which an IC is mounted on a display panel to which the above structures are applied by a COG (Chip On Glass) method or the like.

An electronic device using the display panel or the display module having the above structures is also one embodiment of the present invention. For example, one embodiment of the present invention is an electronic device including the display panel or the display module having the above structures and an antenna, a battery, a housing, a speaker, a microphone, an operation switch, or an operation button.

One embodiment of the present invention includes a display panel, a detector, and a driving device. The display panel has flexibility. The display panel includes a first display element and a second display element. The detector has a function of detecting the brightness of the environment in which the display panel is used and supplying the detection information, and the driving device is supplied with the detection information and drives the display panel. When the detection information includes information less than a predetermined brightness, the driving device supplies a signal for supplying an image signal to the first display element and transmitting light to the first display element. The display device has a function of supplying image information to the second display element when the detection information includes information having a predetermined brightness or more.

Further, according to one aspect of the present invention, the first step of acquiring detection information and the third step when the detection information includes information less than a predetermined brightness, the detection information is equal to or higher than the predetermined brightness. A second step that proceeds to a fourth step if information is included, and a third step that supplies a signal to the second display element that supplies an image signal to the first display element and transmits light. And a fourth step of supplying image information to the second display element.

According to one embodiment of the present invention, a display panel or a display device with low power consumption can be provided. Alternatively, according to one embodiment of the present invention, an all-weather display panel or display device can be provided. Alternatively, according to one embodiment of the present invention, a highly convenient display panel or display device can be provided. Alternatively, according to one embodiment of the present invention, a display panel or a display device with high visibility can be provided regardless of ambient brightness. Alternatively, according to one embodiment of the present invention, a flexible display panel or display device can be provided. Alternatively, according to one embodiment of the present invention, a display panel or a display device can be reduced in thickness or weight.

Alternatively, according to one embodiment of the present invention, a novel display panel, a display device, an input / output device, an electronic device, or the like can be provided.

Note that the description of these effects does not disturb the existence of other effects. Note that one embodiment of the present invention does not necessarily have all of these effects. It should be noted that the effects other than these are naturally obvious from the description of the specification, drawings, claims, etc., and it is possible to extract the other effects from the descriptions of the specification, drawings, claims, etc. It is.

FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 6 illustrates an example of a display panel of one embodiment of the present invention. FIG. 14 illustrates an example of a display device of one embodiment of the present invention. 4A and 4B illustrate an example of a method for driving a display device of one embodiment of the present invention. 10A and 10B illustrate an example of a method for manufacturing a display panel. 10A and 10B illustrate an example of a method for manufacturing a display panel. 10A and 10B illustrate an example of a method for manufacturing a display panel. 10A and 10B illustrate an example of a method for manufacturing a display panel. FIG. 6 is a Cs-corrected high-resolution TEM image in a cross section of a CAAC-OS and a schematic cross-sectional view of the CAAC-OS. The Cs correction | amendment high-resolution TEM image in the plane of CAAC-OS. 6A and 6B illustrate structural analysis by XRD of a CAAC-OS and a single crystal oxide semiconductor. The figure which shows the electron diffraction pattern of CAAC-OS. FIG. 6 shows changes in crystal parts of an In—Ga—Zn oxide due to electron irradiation. FIG. 6 is a schematic diagram illustrating a film formation model of CAAC-OS and nc-OS. 4A and 4B illustrate a crystal and a pellet of InGaZnO ₄ . FIG. 6 is a schematic diagram illustrating a CAAC-OS film formation model. FIG. 6 illustrates an example of an electronic device and a lighting device. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device. FIG. 14 illustrates an example of an electronic device.

Embodiments will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

Note that in structures of the invention described below, the same portions or portions having similar functions are denoted by the same reference numerals in different drawings, and description thereof is not repeated. In addition, in the case where the same function is indicated, the hatch pattern is the same, and there is a case where no reference numeral is given.

In addition, the position, size, range, and the like of each component illustrated in the drawings and the like may not represent the actual position, size, range, or the like for easy understanding. Therefore, the disclosed invention is not necessarily limited to the position, size, range, or the like disclosed in the drawings and the like.

Note that the terms “film” and “layer” can be interchanged with each other depending on circumstances or circumstances. For example, the term “conductive layer” may be changed to the term “conductive film”. Alternatively, for example, the term “insulating film” may be changed to the term “insulating layer” in some cases.

In this specification, “parallel” refers to a state in which two straight lines are arranged at an angle of −10 ° to 10 °. Therefore, the case of −5 ° to 5 ° is also included. Further, “substantially parallel” means a state in which two straight lines are arranged at an angle of −30 ° to 30 °. “Vertical” refers to a state in which two straight lines are arranged at an angle of 80 ° to 100 °. Therefore, the case of 85 ° to 95 ° is also included. Further, “substantially vertical” means a state in which two straight lines are arranged at an angle of 60 ° to 120 °.

In this specification, when a crystal is trigonal or rhombohedral, it is represented as a hexagonal system.

(Embodiment 1)
In this embodiment, a display panel of one embodiment of the present invention will be described with reference to FIGS.

One embodiment of the present invention is a display panel having flexibility, which includes a first display element and a second display element. The first display element overlaps with the second display element. The first display element has a function of emitting light to the second display element side, and the second display element has a variable light transmittance. A display panel having a portion.

In one embodiment of the present invention, the first display element is a light-emitting element, and for example, an organic EL element can be used. The second display element is an element that can be switched between a state that transmits light and a state that does not transmit light (for example, a state that scatters light), for example, a polymer dispersed liquid crystal or a polymer network type. A liquid crystal element using liquid crystal can be applied.

In the display panel of one embodiment of the present invention, an element used for display is switched depending on ambient brightness or an incident state of external light on the display panel (either the first display element or the second display element is used). The user can fully view the display on the display panel regardless of the ambient brightness.

For example, when external light is sufficiently incident on the display panel, display can be performed using external light and the second display element. Thereby, the power consumption of the display panel can be reduced. In addition, even when the surroundings of the display panel are dark and the external light incident on the display panel is small, the first display element is made to transmit light from the first display element through the second display element. The display can be performed using. Thus, according to one embodiment of the present invention, a display panel with high visibility and high convenience or an all-weather display panel can be realized regardless of ambient brightness. The display panel of one embodiment of the present invention can be a flexible display panel by using a flexible material for a substrate or the like. For example, by using an organic resin film for the substrate, the display panel can be made flexible, thin, lightweight, and the like.

The display panel of one embodiment of the present invention may have one second display element with respect to one first display element, or may have two or more. For example, if the number of pixels configured by the first display element is the same as the number of pixels configured by the second display element, the display using the first display element and the second display element are used. Display is preferable because the resolution is equivalent.

FIG. 1A is a top view of the display panel 100. FIG. 1B is a cross-sectional view taken along dashed-dotted line A1-A2 in FIG.

The display panel 100 includes a substrate 101, an element layer 113, an adhesive layer 105, an element layer 117, and a substrate 109. The display panel 100 includes an element layer 113 and an element layer 117 between the substrate 101 and the substrate 109. The display panel 100 includes an adhesive layer 105 between the element layer 113 and the element layer 117.

Each of the substrate 101 and the substrate 109 has flexibility. Note that part of the substrate may have flexibility, or the entire substrate may have flexibility.

Each of the element layer 113 and the element layer 117 includes a display element. Each element layer may further include a transistor or the like for driving the display element. The display element included in the element layer 113 and the display element included in the element layer 117 include an element region 102 (also referred to as a pixel) that overlaps with each other. As shown in FIG. 1A, the element regions 102 are arranged in a matrix and form a display region 110 of the display device.

2A to 2C are cross-sectional views taken along one-dot chain line B1-B2 in FIG. 2A to 2C show modes in which the structure of the display element 103 is different. FIG. 2A is an example in the case where a separate organic EL element is applied to the display element 103. FIG. 2B illustrates an example in which an organic EL element that emits white light is used for the display element 103. FIG. 2C shows an example in which a microresonator structure (also referred to as a microcavity) is combined with an organic EL element.

The display panel 100 includes a substrate 101, an element layer 113, an adhesive layer 105, an element layer 117, and a substrate 109. One element region 102 has a region where one display element 103 and one display element 107 overlap. In the element region 102, the colored layer 181 is disposed so as to overlap with the display element 103 and the display element 107.

The element layer 113 includes the transistor layer 121 and the display element 103.

In this embodiment mode, an organic EL element is used for the display element 103. The display element 103 includes a lower electrode 131, an EL layer 133, and an upper electrode 135. The lower electrode 131 can reflect visible light. The upper electrode 135 can transmit visible light. An end portion of the lower electrode 131 is covered with an insulating layer 141.

When display is performed using a light-emitting element, the plurality of light-emitting elements are independently in a light-emitting state or a non-light-emitting state. Display using a light-emitting element has high visibility even when the periphery of the display panel is dark.

As shown in FIG. 2A, a separate-type light emitting element may be used. By separately coating the light emitting layer or the like, the light emitting color of the light emitting element can be varied depending on the element region 102. For example, a light-emitting layer that exhibits red, yellow, green, blue, or white light can be used for the EL layer.

As shown in FIG. 2B, a light-emitting element that emits white light may be used. The light-emitting element may be a single element having one EL layer or a tandem element having a plurality of EL layers stacked via a charge generation layer. For example, a tandem element that has a fluorescent light emitting unit having a light emitting layer that exhibits blue light, and a phosphorescent light emitting unit that has a light emitting layer that exhibits green light and a light emitting layer that exhibits red light, and that exhibits white light. Can be used.

In addition, as illustrated in FIG. 2C, a microresonator structure can be used in combination with a light-emitting element. For example, the microresonator structure may be configured using the lower electrode and the upper electrode of the light emitting element, and specific light may be efficiently extracted from the light emitting element.

Specifically, a reflective film that reflects visible light is used for the lower electrode 131, and a semi-transmissive / semi-reflective film that transmits part of visible light and reflects part of it is used for the upper electrode 135. Then, the optical distance between the lower electrode 131 and the upper electrode 135 is adjusted so that light having a predetermined wavelength is efficiently extracted.

For example, the first lower electrode 131R, the second lower electrode 131G, and the third lower electrode 131B have optical distances that can resonate desired light from the EL layer 133 and increase its wavelength. Has a function to adjust. Note that the layer for adjusting the optical distance is not limited to the lower electrode 131, and the optical distance may be adjusted by at least one layer constituting the light emitting element.

2B and 2C can manufacture a light-emitting element without coating the EL layer 133 separately, so that the number of manufacturing steps of a display panel can be reduced and productivity can be increased. In addition, high definition of the display panel can be facilitated.

The element layer 117 includes a transistor layer 191 and a display element 107. In addition, the element layer 117 may include a coloring layer 181 and a light shielding layer 183. The coloring layer 181 and the light shielding layer 183 are located between the transistor layer 191 and the display element 107.

In this embodiment, a liquid crystal element is used for the display element 107. The display element 107 includes an electrode 171, a layer 173 containing liquid crystal, and an electrode 175. The electrode 171 can transmit visible light. The electrode 175 can transmit visible light.

In the case of performing display using a liquid crystal element, each of the plurality of liquid crystal elements independently enters a state that transmits visible light or a state that does not transmit visible light (for example, a state that scatters visible light). By using such a liquid crystal element, display using external light as a light source can be performed, and low power consumption of the display panel can be realized.

The liquid crystal element may be an active matrix system or a passive matrix system.

The layer 173 including liquid crystal includes a polymer having a network structure and a liquid crystal phase-separated from the polymer having a network structure.

For the layer 173 containing liquid crystal, polymer dispersed liquid crystal is preferably used. The polymer-dispersed liquid crystal is a liquid crystal method using a layer in which liquid crystal is dispersed in a polymer as a liquid crystal layer. The liquid crystal is a fine particle having a particle size of about 0.1 μm to 20 μm (typically about 1 μm). Note that a PDLC mode is used as a driving method.

For the layer 173 containing liquid crystal, a polymer network type liquid crystal (PNLC (Polymer Network Liquid Crystal)) may be used. The polymer network type liquid crystal is a liquid crystal method using a layer in which liquid crystals are continuously arranged in a polymer network as a liquid crystal layer.

The layer 173 containing liquid crystal has a structure in which liquid crystal grains are dispersed in a polymer layer forming a polymer network.

As the liquid crystal particles, nematic liquid crystal can be used.

Moreover, a photocurable resin can be used as the polymer layer (polymer layer). The photocurable resin may be a monofunctional monomer such as acrylate or methacrylate, may be a polyfunctional monomer such as diacrylate, triacrylate, dimethacrylate, or trimethacrylate, or may be a mixture of these. Further, it may be liquid crystalline or non-liquid crystalline, and both may be mixed. The photo-curing resin may be selected from a resin that cures with light having a wavelength with which the photopolymerization initiator to be used reacts. Typically, an ultraviolet-curing resin can be used.

For example, in the layer 173 containing liquid crystal, a photocurable resin and a photopolymerization initiator react with a liquid crystal material containing a liquid crystal particle using a nematic liquid crystal, a polymer layer using a photocurable resin, and a photopolymerization initiator. It can be formed by curing with irradiation of light of a wavelength.

The photopolymerization initiator may be a radical polymerization initiator that generates radicals by light irradiation, an acid generator that generates acid, or a base generator that generates a base.

As a method for forming the layer 173 containing liquid crystal, a dispenser method (a dropping method) or an injection method in which liquid crystal is injected using a capillary phenomenon can be used.

In addition, since the polymer dispersion type liquid crystal does not align the liquid crystal in advance and does not polarize incident light, the alignment film and the polarizing plate need not be provided.

Therefore, a display panel using a polymer-dispersed liquid crystal does not have an alignment film and a polarizing plate, and therefore does not absorb light by the alignment film and the polarizing plate, so that a bright display screen with higher brightness can be obtained. Therefore, since the light utilization efficiency is good, the power consumption can be reduced. The steps and costs for the alignment film and the polarizing plate can be reduced, and higher throughput and lower cost can be realized. Further, since an alignment film is not provided, a rubbing process is not necessary, electrostatic damage caused by the rubbing process can be prevented, and defects or breakage of the display panel during the manufacturing process can be reduced. Therefore, a display panel can be manufactured with high yield and productivity can be improved. In particular, the transistor has a possibility that the electrical characteristics of the transistor fluctuate significantly due to the influence of static electricity and deviate from the design range. Therefore, it is more effective to use a polymer dispersed liquid crystal material for a display panel having a transistor.

For example, a liquid crystal material having a refractive index anisotropy Δn of 0.15 or more, preferably 0.2 or more can be used. Alternatively, a polymer having a refractive index approximately equal to that of the aligned liquid crystal material can be used.

When the anisotropy of the refractive index of the liquid crystal material is large, the effect of scattering light is enhanced, and the layer 173 containing liquid crystal can be thinned. As a result, the drive voltage can be reduced.

Further, when the relative dielectric constant Δε of the material is large, the driving voltage can be reduced.

For example, the layer 173 containing liquid crystal can be formed by polymerizing a monomer containing a liquid crystal material. Specifically, a composition containing a liquid crystal material and a monomer having a weight percentage of approximately 20% or more and less than 30% is irradiated with ultraviolet rays. The monomer irradiated with ultraviolet rays is polymerized while being phase-separated from the liquid crystal material, so that a layer 173 containing liquid crystal can be formed. For example, an acrylic material can be used for the monomer.

The cell gap, which is the thickness of the layer 173 containing liquid crystal, may be 2 μm to 30 μm (preferably 3 μm to 8 μm). In the present specification, the thickness of the cell gap is the maximum value of the thickness (film thickness) of the liquid crystal layer.

The operating principle of the polymer dispersed liquid crystal will be described. In the case where a voltage is not applied to the electrode 171 and the electrode 175 in the layer 173 containing liquid crystal (also referred to as an off state), the liquid crystal particles dispersed in the polymer layer are randomly arranged so that the refractive index of the polymer and the liquid crystal molecules Therefore, the incident light is scattered by the liquid crystal grains.

On the other hand, when a voltage is applied to the electrodes 171 and 175 (also referred to as an on state), an electric field is formed in the layer 173 containing liquid crystal, and the liquid crystal molecules in the liquid crystal grains are aligned in the direction of the electric field. Since the refractive index of the molecular minor axis substantially matches, the incident light is not scattered by the liquid crystal particles and passes through the layer 173 containing liquid crystal. Therefore, the layer 173 containing liquid crystal becomes light-transmitting and becomes transparent.

As described later, in the display panel of one embodiment of the present invention, by using the reflective electrode included in the display element 103, incident light from the outside is scattered by the layer 173 containing liquid crystal and then reflected by the reflective electrode. Then, since the light again enters the layer 173 containing liquid crystal, a scattering effect equivalent to that of the layer 173 containing liquid crystal twice as thick as the layer 173 containing liquid crystal can be obtained. Therefore, in one embodiment of the present invention, the cell gap can be narrowed. It is preferable that the cell gap can be narrowed because the display element 107 can be driven at a low voltage.

The transistor layer 121 and the transistor layer 191 each include a transistor for driving the display element. Each transistor layer may further include a functional element such as a resistance element or a capacitor element.

A display method of the display panel of one embodiment of the present invention is described with reference to FIGS.

FIG. 3A illustrates an example in which an image is displayed by operating the display element 103. In FIG. 3A, a voltage is applied between the electrode 171 and the electrode 175 in all the element regions 102 (that is, all the pixels). In this state, the layer 173 containing liquid crystal is in a state 174 that transmits visible light, and light emitted from the display element 103 is transmitted and displayed as an image, as indicated by a white arrow. By using the display element 103, display with high visibility or vivid display can be performed even when the display element 103 is used indoors.

Note that when the display element 103 is operated to display an image, the layer 173 containing liquid crystal may be in a state of scattering visible light. For example, when a point defect (bright spot defect) occurs in the display element 103, light emitted from the display element 103 is scattered by the layer 173 containing liquid crystal, thereby reducing the emission intensity of the bright spot and viewing the bright spot. It becomes possible to make it difficult.

FIG. 3B is an example in which the display element 107 is operated to display an image. FIG. 3C shows an enlarged view of a two-dot chain line circle shown in FIG. The display element 107 performs display using reflection of external light. Here, a case where a voltage is applied between the electrode 171 and the electrode 175 in the pixel using the red coloring layer 181R and the pixel using the blue coloring layer 181B is illustrated. The layer 173 including liquid crystal that overlaps with the colored layer 181R and the colored layer 181B enters a state 174 that transmits visible light, and external light (thick dotted lines) incident on these pixels first becomes red light and blue light respectively in the colored layer. And passes through a layer 173 containing liquid crystal. Then, as indicated by a thick solid line arrow, the light is reflected by the lower electrode 131 that reflects visible light, passes through the liquid crystal-containing layer 173 and the colored layer again, and is displayed as an image.

On the other hand, no voltage is applied between the electrode 171 and the electrode 175 of the pixel using the green colored layer 181G, and external light (thick dotted arrow) incident on the pixel becomes green light in the colored layer 181G and includes liquid crystal. After entering the layer 173, it is scattered in various directions within the layer 173 containing liquid crystal, as shown by thin dotted arrows. Further, light that has passed through the layer 173 containing liquid crystal and reached the lower electrode 131 of the display element 103 is also reflected by the lower electrode 131 and is incident again on the layer 173 containing liquid crystal. Scattered in the direction. Further, light that passes through the layer 173 containing liquid crystal again and enters the colored layer 181G again is attenuated by scattering in the layer 173 containing liquid crystal, and is hardly extracted from the display panel. This situation is a black display state on the display panel.

In the display panel of one embodiment of the present invention, the thickness of the colored layer can be approximately half that of a normal transmissive liquid crystal display panel. A thin colored layer is preferable because attenuation of light emitted from the display element 103 can be suppressed. Since the display element 107 uses reflection of external light, it is not necessary to emit light in the display element, and power consumption can be suppressed.

The display panel is not limited to a structure in which black display is performed when the layer 173 including liquid crystal is scattered. For example, as shown in FIG. 2C, in the case where a microresonator structure is used for the display element 103, the display panel may be in a black display state when transmitted through the layer 173 containing liquid crystal.

When the microresonator structure is used, reflection of external light on the display element 103 is suppressed, and external light may be hardly extracted from the display panel. This situation may be a black display state on the display panel. In this case, an image can be displayed by extracting light reflected from the layer 173 containing liquid crystal from the colored layer.

4 to 6 illustrate specific examples of the display panel of one embodiment of the present invention. In addition, description may be abbreviate | omitted about the structure explained in full detail using FIGS. 1-3.

A display panel 100 illustrated in FIG. 4A includes a display region 110 and a driver circuit 202. In the display area 110, element areas are arranged in a matrix. In FIG. 4A, there are three types of element regions (pixels): an element region 102R using a red colored layer, an element region 102G using a green colored layer, and an element region 102B using a blue colored layer. An example is shown. Further, an element region that emits white light (having no colored layer) or an element region that uses a yellow colored layer may be included. In addition, an FPC 445 and an FPC 485 are electrically connected to the display panel illustrated in FIG.

A cross-sectional view taken along alternate long and short dash lines AB, CD, and EF shown in FIG. 4A is shown in FIG.

A display panel 100 illustrated in FIG. 4B is an example in the case where a separate organic EL element is used as the display element 103.

A display panel 100 illustrated in FIG. 4B includes a substrate 101, a display element 103, an adhesive layer 105, a display element 107, an insulating layer 141, a coloring layer 181, a light shielding layer 183, and a substrate 109. The display element 103 includes a lower electrode 131, an EL layer 133, and an upper electrode 135. The display element 107 includes an electrode 171, a layer 173 containing liquid crystal, and an electrode 175.

Further, the display panel 100 illustrated in FIG. 4B includes an adhesive layer 453, an insulating layer 455, a transistor 470a, a transistor 470b, a conductive layer 471, a capacitor 473, an insulating layer 457, an insulating layer 461a, an insulating layer 461b, and a conductive layer. 462, adhesive layer 403, light shielding layer 404, insulating layer 405, insulating layer 406, insulating layer 407, insulating layer 416a, insulating layer 416b, insulating layer 416c, transistor 420a, transistor 420b, conductive layer 436, conductive layer 437, conductive layer 438, a conductive layer 439, a conductive layer 482, and a connection body 483.

The substrate 101 and the insulating layer 455 are attached to each other with an adhesive layer 453. The substrate 109 and the insulating layer 405 are attached to each other with an adhesive layer 403. It is preferable to use a highly moisture-proof film for the insulating layers 405 and 455 because impurities such as water can be prevented from entering a display element such as a light-emitting element or a transistor, and the reliability of the display panel can be improved.

Over the insulating layer 455, a transistor 470a, a transistor 470b, a conductive layer 471, a capacitor 473, and the like are provided.

The transistor 420a and the transistor 470a are included in the display region 110. The transistor 470a is electrically connected to the display element 103. Specifically, the source or the drain of the transistor 470a is electrically connected to the lower electrode 131 through the conductive layer 462. The transistor 420a is electrically connected to the display element 107. Specifically, the source or the drain of the transistor 420a is electrically connected to the electrode 175 through the conductive layer 437 and the conductive layer 439.

The transistor 420b and the transistor 470b are included in the driver circuit 202. A source or a drain of the transistor illustrated in the cross-sectional view along the dashed-dotted line EF is electrically connected to the electrode 171 through the conductive layer 436 and the conductive layer 438.

FIG. 4B illustrates a transistor having a structure having two gate electrodes; however, one embodiment of the present invention is not limited to this. For example, one of two transistors provided on the same plane may have a structure having one gate electrode, and the other may have a structure having two gate electrodes. In addition, for example, the display region 110 and the driver circuit 202 may have different transistor structures.

The conductive layer 471 is electrically connected to an external input terminal that transmits an external signal (a video signal, a clock signal, a start signal, a reset signal, or the like) or a potential to the driver circuit 202. Here, an example in which an FPC 485 is provided as an external input terminal is shown. In order to prevent an increase in the number of steps, the conductive layer 471 is preferably formed using the same material and the same steps as the electrodes and wirings used for the light-emitting portion and the driver circuit portion. The conductive layer 471 is electrically connected to the FPC 485 through the conductive layer 482 and the connection body 483.

A conductive layer used for a transistor, a wiring, or the like provided between the substrate 109 and the light shielding layer 183 may be visually recognized by a user of the display panel. In particular, when a conductive layer with high light reflectivity or a conductive layer with low translucency is used for the electrode or the wiring, the user can easily see the electrode or the wiring. In order to improve the display quality of the display panel, it is preferable that these electrodes and wirings are not easily seen by the user. Therefore, it is preferable to provide the light shielding layer 404. The light-blocking layer 404 is preferably provided between the substrate 109 and the conductive layer closest to the substrate 109 in the thickness direction. Thereby, it can suppress that an electrode and wiring are visually recognized by the user of a display panel, and can aim at the improvement of display quality.

The insulating layer 407 and the insulating layer 457 each have an effect of suppressing diffusion of impurities into the semiconductor included in the transistor. The insulating layer 406, the insulating layer 416a, the insulating layer 416b, the insulating layer 416c, the insulating layer 461a, and the insulating layer 461b each have a planarization function in order to reduce surface unevenness caused by a transistor, a conductive layer, or the like. It is preferred to select the layer.

FIG. 5 illustrates another example of the display panel of one embodiment of the present invention. The display panel shown in FIG. 5 is an example when the display element 103 is combined with an organic EL element and a microresonator structure. In addition, description may be abbreviate | omitted about the structure similar to the structure demonstrated previously.

The display panel illustrated in FIG. 5 includes a substrate 101, a display element 103, an adhesive layer 105, a display element 107, an insulating layer 141, a coloring layer 181, a light shielding layer 183, and a substrate 109. The display element 103 includes an optical adjustment layer 132 between the first electrode and the EL layer.

Further, the display panel illustrated in FIG. 5 includes an adhesive layer 453, an insulating layer 455, a transistor 470a, a transistor 470b, a conductive layer 471, a transistor 474, an insulating layer 457, an insulating layer 459, an insulating layer 461a, an insulating layer 461b, and a conductive layer 462. , An adhesive layer 403, an insulating layer 405, an insulating layer 407, an insulating layer 409, an insulating layer 416, a transistor 420a, a transistor 420b, a conductive layer 421, an insulating layer 428, a connection body 443, an insulating layer 467, and a connection body 483.

In addition, the display panel illustrated in FIG. 5 is attached to a touch panel. The touch panel includes a substrate 888, an adhesive layer 889, an insulating layer 893, a capacitor 880, an insulating layer 897, an adhesive layer 898, and a substrate 899. The display panel substrate 109 and the touch panel substrate 899 are attached to each other with an adhesive layer 879.

The substrate 888 and the substrate 899 have flexibility. For the substrate 888 and the substrate 899, a material that can be used for the substrate 101 or the substrate 109 can be used.

A material that can be used for the adhesive layer 105 can be used for the adhesive layer 879, the adhesive layer 889, and the adhesive layer 898. Note that the touch panel may not have a substrate, and the substrate 109 of the display panel and the insulating layer 897 of the touch panel may be bonded together with an adhesive layer.

For the insulating layer 897, a material that can be used for the insulating layer 405 and the insulating layer 455 can be used.

The capacitor 880 includes a plurality of conductive layers 896, a conductive layer 894 connected to the plurality of conductive layers 896, and an insulating layer 895 between the conductive layers 896 and 894. The plurality of conductive layers 896 are electrically connected through the conductive layer 894. The capacitor 880 may be covered with the insulating layer 893. The conductive layer 896 is electrically connected to the FPC 891 through the connection body 892.

The conductive layer 894 and the conductive layer 896 are formed using a light-transmitting conductive material. As the light-transmitting conductive material, a conductive oxide such as indium oxide, indium tin oxide, indium zinc oxide, zinc oxide, or zinc oxide to which gallium is added can be used. Note that a film containing graphene can also be used. The film containing graphene can be formed, for example, by reducing a film containing graphene oxide formed in a film shape. Examples of the reduction method include a method of applying heat.

Note that a conductive film such as the conductive layer 894 and the conductive layer 896, that is, a material that can be used for a wiring or an electrode included in the touch panel, for example, is preferably a transparent conductive film such as ITO or indium zinc oxide. As other materials, for example, materials having a low resistance value are desirable. As an example, silver, copper, aluminum, carbon nanotube, graphene, metal halide (such as silver halide), or the like may be used. Furthermore, a metal nanowire configured using a large number of conductors that are very thin (for example, a diameter of several nanometers) may be used. Or you may use the metal mesh which made the conductor a mesh shape. As an example, Ag nanowire, Cu nanowire, Al nanowire, Ag mesh, Cu mesh, or Al mesh may be used. In the case of Ag nanowires, the light transmittance can be 89% or more and the sheet resistance value can be 40Ω / □ or more and 100Ω / □ or less. Note that since the transmittance is high, a metal nanowire, a metal mesh, a carbon nanotube, graphene, or the like may be used for an electrode used for a display element, for example, a pixel electrode or a common electrode.

The transistor 474 is included in the display area 110. FIG. 5 illustrates an example in which a transistor having a structure having one gate electrode is applied to the element region and a transistor having a structure having two gate electrodes is applied to the driver circuit.

The conductive layer 421 is electrically connected to an external input terminal that transmits an external signal or potential to the driving circuit 202. Here, an example in which an FPC 445 is provided as an external input terminal is shown. The conductive layer 421 is electrically connected to the FPC 445 through the connection body 443.

The insulating layer 409 and the insulating layer 459 each have an effect of suppressing diffusion of impurities into the semiconductor included in the transistor.

The insulating layer 428 functions as a spacer and can adjust the distance between the pair of electrodes included in the display element 107. The insulating layer 467 functions as a spacer and can adjust the distance between the pair of electrodes included in the display element 103.

FIG. 6 illustrates another example of the display panel of one embodiment of the present invention. The display panel shown in FIG. 5 is a top emission type, but FIG. 6 shows an example of a bottom emission type. In addition, description may be abbreviate | omitted about the structure similar to the structure demonstrated previously.

The display panel illustrated in FIG. 6 includes a substrate 101, a display element 103, an adhesive layer 105 a, an adhesive layer 105 b, a display element 107, an insulating layer 141, a colored layer 181, a light shielding layer 183, and a substrate 109.

Further, the display panel illustrated in FIG. 6 includes an adhesive layer 453, a transistor 470a, a transistor 470b, a conductive layer 471, an insulating layer 455, an insulating layer 457, an insulating layer 459, an insulating layer 461a, an insulating layer 461b, a conductive layer 462, and an adhesive layer. 403, an insulating layer 405, an insulating layer 407, an insulating layer 409, an insulating layer 416, a transistor 420a, a transistor 420b, a conductive layer 421, an insulating layer 428, a connection body 443, a substrate 451, an insulating layer 467, and a connection body 483.

The substrate 451 has flexibility. For the substrate 451, a material that can be used for the substrate 101 or the substrate 109 can be used.

FIG. 6 illustrates an example in which the insulating layer 455 and the substrate 451 are bonded to each other with the adhesive layer 105a, and the electrodes of the substrate 451 and the display element 107 are bonded to each other with the adhesive layer 105b. The display panel may not include the substrate 451 and the insulating layer 455 and the electrode of the display element 107 may be attached to each other with an adhesive layer.

6 illustrates an example in which a transistor having a structure different from that in FIG. 5 is used. Specifically, after a gate electrode and a gate insulating film are formed over a part of a semiconductor film which is a channel formation region of a transistor, a region of the semiconductor film that is not covered with the gate electrode and the gate insulating film is formed. A transistor having a self-aligned structure in which a source region and a drain region are formed by reducing resistance is shown.

Next, materials that can be used for the display panel will be described. In addition, description may be abbreviate | omitted about the structure demonstrated previously in this specification.

For the substrate 101 and the substrate 109, materials such as glass, quartz, organic resin, metal, and alloy can be used. A material that transmits visible light is used for the substrate on the display surface side of the display panel.

In particular, it is preferable to use a flexible substrate. For example, organic resin or flexible glass, metal, or alloy can be used.

Since the specific gravity of an organic resin is smaller than that of glass, it is preferable to use an organic resin as a flexible substrate because the display panel can be reduced in weight compared to the case of using glass.

It is preferable to use a material having high toughness for the substrate. Thereby, it is possible to realize a display panel that has excellent impact resistance and is not easily damaged. For example, by using an organic resin substrate, a thin metal substrate, or an alloy substrate, it is possible to realize a display panel that is lighter and less likely to be damaged than when a glass substrate is used.

Metal materials and alloy materials are preferable because they have high thermal conductivity and can easily conduct heat to the entire substrate, which can suppress a local temperature rise of the display panel. The thickness of the substrate using a metal material or an alloy material is preferably 10 μm to 200 μm, and more preferably 20 μm to 50 μm.

The material constituting the metal substrate or the alloy substrate is not particularly limited. For example, aluminum, copper, nickel, or an alloy of a metal such as an aluminum alloy or stainless steel can be preferably used.

In addition, when a material having a high thermal emissivity is used for the substrate, it is possible to suppress an increase in the surface temperature of the display panel, and it is possible to suppress destruction of the display panel and a decrease in reliability. For example, the substrate may have a stacked structure of a metal substrate and a layer having a high thermal emissivity (for example, a metal oxide or a ceramic material can be used).

The flexible substrate has a hard coat layer (for example, a silicon nitride layer) that protects the surface of the device from scratches, and a layer (for example, an aramid resin layer) that can disperse the pressure. Etc.) and the like.

The flexible substrate can be used by stacking a plurality of layers. In particular, when the glass layer is used, the barrier property against water and oxygen can be improved and a highly reliable display panel can be obtained.

For example, in this specification and the like, transistors and display elements can be formed using various substrates. The kind of board | substrate is not limited to a specific thing. Examples of the substrate include a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate having stainless steel foil, and a tungsten substrate. , A substrate having a tungsten foil, a flexible substrate, a laminated film, a paper containing a fibrous material, or a base film. Examples of the glass substrate include barium borosilicate glass, aluminoborosilicate glass, and soda lime glass. Examples of the flexible substrate, the laminated film, and the base film include the following. For example, there are plastics represented by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), and polytetrafluoroethylene (PTFE). Another example is a synthetic resin such as acrylic. Alternatively, examples include polypropylene, polyester, polyvinyl fluoride, and polyvinyl chloride. Alternatively, examples include polyester, polyamide, polyimide, aramid, epoxy, inorganic vapor deposition film, and paper. In particular, by manufacturing a transistor using a semiconductor substrate, a single crystal substrate, an SOI substrate, or the like, a transistor with small variation in characteristics, size, or shape, high current capability, and small size can be manufactured. . When a circuit is formed using such transistors, the power consumption of the circuit can be reduced or the circuit can be highly integrated.

Alternatively, a flexible substrate may be used as the substrate, and the transistor may be formed directly over the flexible substrate. Alternatively, a separation layer may be provided between the substrate and the transistor. The separation layer can be used to separate a semiconductor device from another substrate and transfer it to another substrate after a semiconductor device is partially or entirely completed thereon. At that time, the transistor can be transferred to a substrate having poor heat resistance or a flexible substrate. Note that, for example, a structure of a laminated structure of an inorganic film of a tungsten film and a silicon oxide film or a structure in which an organic resin film such as polyimide is formed over a substrate can be used for the above-described release layer.

That is, a transistor may be formed using a certain substrate, and then the transistor may be transferred to another substrate, and the transistor may be disposed on another substrate. Examples of a substrate to which a transistor is transferred include a paper substrate, a cellophane substrate, an aramid film substrate, a polyimide film substrate, a stone substrate, a wood substrate, a cloth substrate (natural fiber) in addition to the above-described substrate capable of forming a transistor. (Silk, cotton, hemp), synthetic fibers (including nylon, polyurethane, polyester) or recycled fibers (including acetate, cupra, rayon, recycled polyester), leather substrates, rubber substrates, and the like. By using these substrates, it is possible to form a transistor with good characteristics, a transistor with low power consumption, manufacture a device that is not easily broken, impart heat resistance, reduce weight, or reduce thickness.

For the adhesive layer 105, various curable adhesives such as an ultraviolet curable photocurable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, and the like. In particular, a material with low moisture permeability such as an epoxy resin is preferable. Alternatively, a two-component mixed resin may be used. Further, an adhesive sheet or the like may be used.

Further, the resin may contain a desiccant. For example, a substance that adsorbs moisture by chemical adsorption, such as an alkaline earth metal oxide (such as calcium oxide or barium oxide), can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. The inclusion of a desiccant is preferable because impurities such as moisture can be prevented from entering the functional element and the reliability of the display panel is improved.

Moreover, the light extraction efficiency from a light emitting element can be improved by mixing the said resin with a filler with a high refractive index, or a light-scattering member. For example, titanium oxide, barium oxide, zeolite, zirconium, or the like can be used.

The structure of the transistor included in the display panel is not particularly limited. For example, a staggered transistor or an inverted staggered transistor may be used. Further, a top-gate or bottom-gate transistor structure may be employed. A semiconductor material used for the transistor is not particularly limited, and examples thereof include silicon, germanium, and an organic semiconductor. Alternatively, an oxide semiconductor containing at least one of indium, gallium, and zinc, such as an In—Ga—Zn-based metal oxide, may be used.

In particular, when a transistor whose leakage current is extremely small in an off state is used for the transistor connected to the display element 103 and the transistor connected to the display element 107, the time during which an image signal can be held can be lengthened. it can. For example, image signal writing is performed at a frequency of 11.6 μHz (once per day) or more and less than 0.1 Hz (0.1 per second), preferably 0.28 mHz (once per hour) or more and 1 Hz (1 Images can be retained even with a frequency less than once per second). As a result, the frequency of writing image signals can be reduced. As a result, the power consumption of the display panel 100 can be reduced. Of course, the image signal can be written at a frequency of 30 Hz (30 times per second) or more, preferably 60 Hz (60 times per second) or more and less than 960 Hz (960 times per second).

As a transistor with extremely small leakage current in the off state, for example, a transistor in which an oxide semiconductor is used for a semiconductor layer can be used. Specifically, it is represented by an In-M-Zn oxide containing at least indium (In), zinc (Zn), and M (metal such as Al, Ga, Ge, Y, Zr, Sn, La, Ce, or Hf). An oxide semiconductor containing the material to be used can be preferably used for the semiconductor layer. Or it is preferable that both In and Zn are included.

For example, when the voltage between the source and the drain is about 0.1 V, 5 V, or 10 V, the off-current normalized by the channel width of the transistor is reduced to several yA / μm to several zA / μm. It becomes possible.

Examples of the oxide semiconductor that forms the oxide semiconductor film include an In—Ga—Zn-based oxide, an In—Al—Zn-based oxide, an In—Sn—Zn-based oxide, an In—Hf—Zn-based oxide, In-La-Zn-based oxide, In-Ce-Zn-based oxide, In-Pr-Zn-based oxide, In-Nd-Zn-based oxide, In-Sm-Zn-based oxide, In-Eu-Zn Oxide, In-Gd-Zn oxide, In-Tb-Zn oxide, In-Dy-Zn oxide, In-Ho-Zn oxide, In-Er-Zn oxide, In -Tm-Zn-based oxide, In-Yb-Zn-based oxide, In-Lu-Zn-based oxide, In-Sn-Ga-Zn-based oxide, In-Hf-Ga-Zn-based oxide, In- Al-Ga-Zn-based oxide, In-Sn-Al-Zn-based oxide, In-Sn-Hf- n based oxide, In-Hf-Al-Zn-based oxide can be used an In-Ga-based oxide.

Note that here, an In—Ga—Zn-based oxide means an oxide containing In, Ga, and Zn as its main components, and there is no limitation on the ratio of In, Ga, and Zn. Moreover, metal elements other than In, Ga, and Zn may be contained.

An oxide semiconductor that can be favorably used for one embodiment of the present invention will be described in detail in Embodiment 4.

There is no particular limitation on the crystallinity of a semiconductor material used for the transistor, and any of an amorphous semiconductor and a semiconductor having crystallinity (a microcrystalline semiconductor, a polycrystalline semiconductor, a single crystal semiconductor, or a semiconductor partially including a crystal region) is used. May be used. It is preferable to use a crystalline semiconductor because deterioration of transistor characteristics can be suppressed. For example, single crystal silicon, polysilicon, amorphous silicon, or the like can be applied to the semiconductor layer of the transistor.

In order to stabilize the characteristics of the transistor, it is preferable to provide a base film. As the base film, an inorganic insulating film such as a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or a silicon nitride oxide film can be used, which can be formed as a single layer or a stacked layer. The base film is formed by sputtering, CVD (Chemical Vapor Deposition) (plasma CVD, thermal CVD, MOCVD (Metal Organic CVD), etc.), ALD (Atomic Layer Deposition), coating, printing, etc. it can. Note that the base film is not necessarily provided if not necessary.

As the light-emitting element, an element capable of self-emission can be used, and an element whose luminance is controlled by current or voltage is included in its category. For example, a light emitting diode (LED), an organic EL element, an inorganic EL element, or the like can be used.

The light emitting element may be any of a top emission type, a bottom emission type, and a dual emission type. A conductive film that transmits visible light is used for the electrode from which light is extracted. In addition, a conductive film that reflects visible light is preferably used for the electrode from which light is not extracted.

The conductive film that transmits visible light is formed using, for example, indium oxide, indium tin oxide (ITO), indium zinc oxide, zinc oxide (ZnO), zinc oxide to which gallium is added, or the like. Can do. In addition, a metal material such as gold, silver, platinum, magnesium, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, palladium, or titanium, an alloy including these metal materials, or a nitride of these metal materials (for example, Titanium nitride) can also be used by forming it thin enough to have translucency. In addition, a stacked film of the above materials can be used as a conductive layer. For example, it is preferable to use a laminated film of silver and magnesium alloy and ITO because the conductivity can be increased. Further, graphene or the like may be used.

For the conductive film that reflects visible light, for example, a metal material such as aluminum, gold, platinum, silver, nickel, tungsten, chromium, molybdenum, iron, cobalt, copper, or palladium, or an alloy including these metal materials is used. Can do. In addition, lanthanum, neodymium, germanium, or the like may be added to the metal material or alloy. Also, alloys containing aluminum (aluminum alloys) such as aluminum and titanium alloys, aluminum and nickel alloys, aluminum and neodymium alloys, aluminum, nickel, and lanthanum alloys (Al-Ni-La), silver and copper Or an alloy containing silver such as an alloy of silver, palladium and copper (also referred to as Ag-Pd-Cu or APC), an alloy of silver and magnesium, or the like. An alloy containing silver and copper is preferable because of its high heat resistance. Furthermore, the oxidation of the aluminum alloy film can be suppressed by stacking the metal film or the metal oxide film in contact with the aluminum alloy film. Examples of the material for the metal film and metal oxide film include titanium and titanium oxide. Alternatively, the conductive film that transmits visible light and a film made of a metal material may be stacked. For example, a laminated film of silver and ITO, a laminated film of an alloy of silver and magnesium and ITO, or the like can be used.

When the microresonator structure is combined, a semi-transmissive / semi-reflective electrode can be used as the upper electrode of the light emitting element. The semi-transmissive / semi-reflective electrode is formed of a conductive material having reflectivity and a conductive material having translucency. Examples of the conductive material include a conductive material having a visible light reflectance of 20% to 80%, preferably 40% to 70%, and a resistivity of 1 × 10 ⁻² Ω · cm or less. Can be mentioned. The semi-transmissive / semi-reflective electrode can be formed using one or more kinds of conductive metals, alloys, conductive compounds, and the like. In particular, it is preferable to use a material having a small work function (3.8 eV or less). For example, elements belonging to Group 1 or Group 2 of the periodic table (alkali metals such as lithium and cesium, alkaline earth metals such as calcium and strontium, magnesium, etc.), and alloys containing these elements (eg, Ag-Mg) Al-Li), rare earth metals such as europium and ytterbium, alloys containing these rare earth metals, aluminum, silver, and the like can be used. The semi-transmissive / semi-reflective electrode can be formed by sputtering, vapor deposition, printing, coating, or the like.

The electrodes may be formed using a vapor deposition method or a sputtering method, respectively. In addition, it can be formed using a discharge method such as an inkjet method, a printing method such as a screen printing method, or a plating method.

When a voltage higher than the threshold voltage of the light emitting element is applied between the lower electrode 131 and the upper electrode 135, holes are injected into the EL layer 133 from the anode side and electrons are injected from the cathode side. The injected electrons and holes are recombined in the EL layer 133, and the light-emitting substance contained in the EL layer 133 emits light.

The EL layer 133 includes at least a light emitting layer. The EL layer 133 is a layer other than the light-emitting layer, such as a substance having a high hole-injecting property, a substance having a high hole-transporting property, a hole blocking material, a substance having a high electron-transporting property, a substance having a high electron-injecting property, or a bipolar property A layer containing a substance (a substance having a high electron transporting property and a high hole transporting property) or the like may be further included.

For the EL layer 133, either a low molecular compound or a high molecular compound can be used, and an inorganic compound may be included. The layers constituting the EL layer 133 can be formed by a method such as a vapor deposition method (including a vacuum vapor deposition method), a transfer method, a printing method, an ink jet method, or a coating method.

The light emitting element may contain two or more light emitting substances. Thereby, for example, a white light emitting element can be realized. For example, white light emission can be obtained by selecting the light emitting material so that the light emission of each of the two or more light emitting materials has a complementary color relationship. For example, a light-emitting substance that emits light such as R (red), G (green), B (blue), Y (yellow), or O (orange), or spectral components of two or more colors of R, G, and B A light-emitting substance that emits light containing can be used. For example, a light-emitting substance that emits blue light and a light-emitting substance that emits yellow light may be used. At this time, the emission spectrum of the luminescent material that emits yellow light preferably includes green and red spectral components. In addition, the emission spectrum of the light-emitting element preferably has two or more peaks in a visible wavelength range (for example, 350 nm to 750 nm or less, or 400 nm to 800 nm or less).

The EL layer 133 may include a plurality of light emitting layers. In the EL layer 133, the plurality of light-emitting layers may be stacked in contact with each other or may be stacked via a separation layer. For example, a separation layer may be provided between the fluorescent light emitting layer and the phosphorescent light emitting layer.

The separation layer can be provided, for example, to prevent energy transfer (particularly triplet energy transfer) by a Dexter mechanism from an excited state of the phosphorescent material generated in the phosphorescent light emitting layer to the fluorescent material in the fluorescent light emitting layer. The separation layer may have a thickness of about several nm. Specifically, the thickness is 0.1 nm to 20 nm, or 1 nm to 10 nm, or 1 nm to 5 nm. The separation layer includes a single material (preferably a bipolar substance) or a plurality of materials (preferably a hole transport material and an electron transport material).

The separation layer may be formed using a material included in the light emitting layer in contact with the separation layer. This facilitates the production of the light emitting element and reduces the driving voltage. For example, when the phosphorescent light-emitting layer is formed of a host material, an assist material, and a phosphorescent material (guest material), the separation layer may be formed using the host material and the assist material. In other words, the separation layer has a region not containing a phosphorescent material, and the phosphorescent light-emitting layer has a region containing a phosphorescent material. Thereby, the separation layer and the phosphorescent light emitting layer can be deposited with or without the phosphorescent material. Further, with such a structure, the separation layer and the phosphorescent light emitting layer can be formed in the same chamber. Thereby, manufacturing cost can be reduced.

The light shielding layer is provided between the adjacent colored layers. The light shielding layer shields light from adjacent light emitting elements and suppresses color mixing between adjacent light emitting elements. Here, light leakage can be suppressed by providing the end portion of the colored layer so as to overlap the light shielding layer. For the light-blocking layer, a material that blocks light emitted from the light-emitting element can be used. For example, a black matrix may be formed using a metal material, a resin material containing a pigment, or a dye. Note that the light shielding layer is preferably provided in a region other than the light emitting portion such as the drive circuit portion because unintended light leakage due to guided light or the like can be suppressed.

The colored layer is a colored layer that transmits light in a specific wavelength band. For example, a color filter that transmits light in a red, green, blue, or yellow wavelength band can be used. Each colored layer is formed at a desired position using a variety of materials by a printing method, an inkjet method, an etching method using a photolithography method, or the like. In the white sub-pixel, a transparent or white resin may be disposed so as to overlap the light emitting element.

As the insulating layer 405 and the insulating layer 455, an insulating film with high moisture resistance is preferably used. Alternatively, the insulating layer 405 and the insulating layer 455 preferably have a function of preventing unintended diffusion of impurities into the light-emitting element or the like.

Examples of the highly moisture-proof insulating film include a film containing nitrogen and silicon such as a silicon nitride film and a silicon nitride oxide film, and a film containing nitrogen and aluminum such as an aluminum nitride film. Alternatively, a silicon oxide film, a silicon oxynitride film, an aluminum oxide film, or the like may be used.

For example, the moisture permeation amount of the highly moisture-proof insulating film is 1 × 10 ⁻⁵ [g / m ² · day] or less, preferably 1 × 10 ⁻⁶ [g / m ² · day] or less, more preferably 1 × 10 ⁻⁷ [g / m ² · day] or less, more preferably 1 × 10 ⁻⁸ [g / m ² · day] or less.

The light-emitting element is preferably provided between a pair of insulating films with high moisture resistance. Thereby, impurities such as water can be prevented from entering the light emitting element, and a decrease in the reliability of the display panel can be suppressed.

As the insulating layer 407, the insulating layer 409, the insulating layer 457, and the insulating layer 459, for example, an inorganic insulating film such as a silicon oxide film, a silicon oxynitride film, or an aluminum oxide film can be used. As the insulating layer 406, the insulating layer 416a, the insulating layer 416b, the insulating layer 416c, the insulating layer 461a, and the insulating layer 461b, for example, an organic material such as polyimide, acrylic, polyamide, polyimide amide, or benzocyclobutene resin is used. Each can be used. Further, a low dielectric constant material (low-k material) or the like can be used. Each insulating layer may be formed by stacking a plurality of insulating films.

The insulating layer 141 is formed using an organic insulating material or an inorganic insulating material. As the resin, for example, polyimide resin, polyamide resin, acrylic resin, siloxane resin, epoxy resin, phenol resin, or the like can be used. In particular, it is preferable to use a photosensitive resin material and form an opening on the lower electrode so that the side wall of the opening has an inclined surface formed with a continuous curvature.

A method for forming the insulating layer 141 is not particularly limited, and a photolithography method, a sputtering method, a vapor deposition method, a droplet discharge method (inkjet method or the like), a printing method (screen printing, offset printing, or the like) may be used.

The insulating layer 428 and the insulating layer 467 can be formed using an inorganic insulating material, an organic insulating material, a metal material, or the like, respectively. For example, as the inorganic insulating material and the organic insulating material, various materials that can be used for the insulating layer can be given.

A conductive layer used for a display panel that functions as an electrode or wiring of a transistor or an auxiliary electrode of a light-emitting element is a metal material such as molybdenum, titanium, chromium, tantalum, tungsten, aluminum, copper, neodymium, or scandium, or these An alloy material containing any of the above elements can be used to form a single layer or a stacked layer. The conductive layer may be formed using a conductive metal oxide. Examples of the conductive metal oxide include indium oxide (such as In ₂ O ₃ ), tin oxide (such as SnO ₂ ), ZnO, ITO, indium zinc oxide (such as In ₂ O ₃ —ZnO), or a metal oxide material thereof. The one containing silicon oxide can be used.

As the connection body, various anisotropic conductive films (ACF: Anisotropic Conductive Film), anisotropic conductive pastes (ACP: Anisotropic Conductive Paste), and the like can be used.

In this specification and the like, a display element, a display panel which is a panel including a display element, a light-emitting element, and a light-emitting panel which is a panel including a light-emitting element can have various modes or have various elements. . Examples of display elements, display panels, light-emitting elements, or light-emitting panels include EL elements (EL elements including organic and inorganic substances, organic EL elements, inorganic EL elements), LEDs (white LEDs, red LEDs, green LEDs, blue LEDs, etc.) ), Transistor (transistor that emits light in response to current), electron-emitting device, liquid crystal device, electronic ink, electrophoretic device, grating light valve (GLV), plasma display panel (PDP), MEMS (micro electro mechanical system) ), Digital micromirror device (DMD), DMS (digital micro shutter), IMOD (interference modulation) element, shutter type MEMS display element, optical interference type MEMS display element, electro Wetti Grayed element, a piezoelectric ceramic display, such as carbon nanotubes, the electrical magnetic action, those having contrast, brightness, reflectance, a display medium such as transmittance changes. An example of a display panel using an EL element is an EL display. As an example of a display panel using an electron-emitting device, there is a field emission display (FED), a SED type flat display (SED: Surface-Conduction Electron-Emitter Display), or the like. As an example of a display panel using a liquid crystal element, there is a liquid crystal display (a transmissive liquid crystal display, a transflective liquid crystal display, a reflective liquid crystal display, a direct view liquid crystal display, a projection liquid crystal display) and the like. An example of a display panel using electronic ink, electronic powder fluid, or an electrophoretic element is electronic paper. Note that when a transflective liquid crystal display or a reflective liquid crystal display is realized, a part or all of the pixel electrodes may have a function as a reflective electrode. For example, part or all of the pixel electrode may have aluminum, silver, or the like. Further, in that case, a memory circuit such as an SRAM can be provided under the reflective electrode. Thereby, power consumption can be further reduced. In addition, when using LED, you may arrange | position graphene or graphite under the electrode and nitride semiconductor of LED. Graphene or graphite may be a multilayer film in which a plurality of layers are stacked. Thus, by providing graphene or graphite, a nitride semiconductor, for example, an n-type GaN semiconductor layer having a crystal can be easily formed thereon. Furthermore, a p-type GaN semiconductor layer having a crystal or the like can be provided thereon to form an LED. Note that an AlN layer may be provided between graphene or graphite and an n-type GaN semiconductor layer having a crystal. Note that the GaN semiconductor layer of the LED may be formed by MOCVD. However, by providing graphene, the GaN semiconductor layer of the LED can be formed by a sputtering method.

For example, in this specification and the like, an active matrix method in which an active element (an active element or a nonlinear element) is included in a pixel or a passive matrix method in which an active element is not included in a pixel can be used.

In the active matrix system, not only transistors but also various active elements can be used. For example, MIM (Metal Insulator Metal) or TFD (Thin Film Diode) can be used. Since these elements have few manufacturing steps, manufacturing cost can be reduced or yield can be improved. Alternatively, since these elements have small element sizes, the aperture ratio can be improved, and power consumption and luminance can be reduced.

In the passive matrix method, since no active element is used, manufacturing steps can be reduced, manufacturing cost can be reduced, or yield can be improved. Alternatively, in the passive matrix method, an active element is not used, so that the aperture ratio can be improved and low power consumption, high luminance, or the like can be achieved.

Note that the display panel of one embodiment of the present invention may be used as a display panel or an illumination panel. For example, it may be used as a light source such as a backlight or a front light, that is, a lighting panel for a display panel.

As described above, the display panel of one embodiment of the present invention includes the display element 103 and the display element 107, the display element 107 includes polymer dispersed liquid crystal, and the display element 107 emits light emitted from the display element 103. The function which can be made into the state which permeate | transmits or is scattered. Accordingly, the display element can be selectively used, and a novel display panel with low power consumption and excellent convenience can be provided.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 2)
In this embodiment, a display device and a driving method thereof according to one embodiment of the present invention will be described with reference to FIGS.

FIG. 7 is a block diagram illustrating a display device of one embodiment of the present invention. A display device 200 illustrated in FIG. 7 includes a display panel 100, a detector 215, and a driving device 213.

As the display panel 100, the display panel of one embodiment of the present invention described in Embodiment 1 can be used.

The detector 215 can detect the brightness of the environment in which the display device 200 is used. The detector 215 can supply detection information including the detected brightness information to the driving device 213. For example, a circuit that detects and outputs ambient illuminance based on a photoelectric conversion element and a signal supplied by the photoelectric conversion element can be used for the detector 215. The detector 215 may include, for example, a photodiode, a CCD, or a CMO image sensor.

The driving device 213 can drive the display panel 100 by determining a driving method of the display panel 100 based on information supplied from the detector 215.

The drive device 213 supplies an image signal to the display element 103 and supplies a signal for transmitting light to the display element 107 when the detection information includes information less than a predetermined brightness. A function of supplying image information to the display element 107 when information having a predetermined brightness or more is included.

Next, an example of a method for driving the display device 200 will be described using the flowchart shown in FIG.

First, the illuminance is detected using the detector 215 in the display device 200 (step S101).

If the detected illuminance in step S101 is less than the predetermined illuminance X, a transmission signal is supplied to the display element 107 (step S102). Thereby, the display element 107 is in a state of transmitting light. And an image signal is supplied to the display element 103 and an image is displayed (step S103).

On the other hand, if the detected illuminance is greater than or equal to the predetermined illuminance X in step S101, the display element 103 is turned off (step S104). And an image signal is supplied to the display element 107 and an image is displayed (step S105).

Then, after a time set in advance by a timer or the like has elapsed, the process returns to step S101, illuminance is detected again, and the above steps are repeated.

Although the display element 103 causes power consumption to display an image by self-emission, the display element 107 displays an image using external light. Therefore, in an environment with high illuminance, power consumption of the display device can be significantly reduced by displaying an image using the external light and the display element 107. In addition, since the display state of the display device of one embodiment of the present invention can be automatically changed depending on illuminance, it is not always necessary to set which display element the user uses. Therefore, a display device with low power consumption and excellent convenience can be provided.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 3)
In this embodiment, a method for manufacturing a display panel of one embodiment of the present invention will be described with reference to FIGS.

First, the separation layer 203 is formed over the manufacturing substrate 201, and the separation layer 205 is formed over the separation layer 203 (FIG. 9A). Further, the separation layer 223 is formed over the manufacturing substrate 221 and the layer to be separated 225 is formed over the separation layer 223 (FIG. 9B).

Here, an example in which an island-shaped release layer is formed is shown, but the present invention is not limited thereto. In this step, when the layer to be peeled is peeled from the manufacturing substrate, a material that causes peeling in the interface between the manufacturing substrate and the peeling layer, the interface between the peeling layer and the peeling layer, or the peeling layer is selected. In this embodiment, the case where separation occurs at the interface between the layer to be peeled and the layer to be peeled is illustrated, but the present invention is not limited to this depending on the combination of materials used for the layer to be peeled and the layer to be peeled. Note that in the case where the layer to be peeled has a stacked structure, a layer in contact with the peeling layer is particularly referred to as a first layer.

For example, in the case where the separation layer has a stacked structure of a tungsten film and a tungsten oxide film, separation occurs at the interface between the tungsten film and the tungsten oxide film (or in the vicinity of the interface), so that a part of the separation layer is formed on the separation layer side. (Here, a tungsten oxide film) may remain. Further, the release layer remaining on the peeled layer side may be removed thereafter.

As the manufacturing substrate, a substrate having heat resistance that can withstand at least a processing temperature during the manufacturing process is used. As the manufacturing substrate, for example, a glass substrate, a quartz substrate, a sapphire substrate, a semiconductor substrate, a ceramic substrate, a metal substrate, a resin substrate, a plastic substrate, or the like can be used.

In the case where a glass substrate is used as the manufacturing substrate, an insulating film such as a silicon oxide film, a silicon oxynitride film, a silicon nitride film, or a silicon nitride oxide film is formed as a base film between the manufacturing substrate and the separation layer. This is preferable because it can prevent contamination from water.

The peeling layer is formed using an element selected from tungsten, molybdenum, titanium, tantalum, niobium, nickel, cobalt, zirconium, zinc, ruthenium, rhodium, palladium, osmium, iridium, and silicon, an alloy material containing the element, or the element. It can be formed using a compound material or the like. The crystal structure of the layer containing silicon may be any of amorphous, microcrystalline, and polycrystalline. Alternatively, a metal oxide such as aluminum oxide, gallium oxide, zinc oxide, titanium dioxide, indium oxide, indium tin oxide, indium zinc oxide, or In—Ga—Zn oxide may be used. A refractory metal material such as tungsten, titanium, or molybdenum is preferably used for the separation layer because the degree of freedom in the formation process of the layer to be separated is increased.

The release layer can be formed by, for example, a sputtering method, a plasma CVD method, a coating method (including a spin coating method, a droplet discharge method, a dispensing method, or the like), a printing method, or the like. The thickness of the release layer is, for example, 10 nm to 200 nm, preferably 20 nm to 100 nm.

In the case where the separation layer has a single-layer structure, a tungsten layer, a molybdenum layer, or a layer containing a mixture of tungsten and molybdenum is preferably formed. Alternatively, a layer containing tungsten oxide or oxynitride, a layer containing molybdenum oxide or oxynitride, or a layer containing an oxide or oxynitride of a mixture of tungsten and molybdenum may be formed. Note that the mixture of tungsten and molybdenum corresponds to, for example, an alloy of tungsten and molybdenum.

In the case of forming a stacked structure of a layer containing tungsten and a layer containing tungsten oxide as the peeling layer, a layer containing tungsten is formed, and an insulating film formed of an oxide is formed thereon. Alternatively, the fact that a layer containing an oxide of tungsten is formed at the interface between the tungsten layer and the insulating film may be utilized. Further, the surface of the layer containing tungsten is subjected to thermal oxidation treatment, oxygen plasma treatment, nitrous oxide (N ₂ O) plasma treatment, treatment with a solution having strong oxidizing power such as ozone water, and the like to form tungsten oxide. An included layer may be formed. Plasma treatment and heat treatment may be performed in oxygen, nitrogen, nitrous oxide alone, or a mixed gas atmosphere of the gas and other gases. By changing the surface state of the release layer by the plasma treatment or the heat treatment, the adhesion between the release layer and an insulating film to be formed later can be controlled.

Note that in the case where peeling is possible at the interface between the manufacturing substrate and the layer to be peeled, the peeling layer is not necessarily provided. For example, glass is used as a manufacturing substrate, and an organic resin such as polyimide, polyester, polyolefin, polyamide, polycarbonate, or acrylic is formed in contact with the glass. Next, the adhesion between the manufacturing substrate and the organic resin is improved by performing laser irradiation or heat treatment. Then, an insulating film, a transistor, or the like is formed over the organic resin. Then, laser irradiation can be performed at an energy density higher than that of the previous laser irradiation, or heat treatment can be performed at a temperature higher than that of the previous heat treatment, so that separation can be performed at the interface between the formation substrate and the organic resin. Further, at the time of peeling, the liquid may penetrate into the interface between the manufacturing substrate and the organic resin to be separated.

In this method, since an insulating film, a transistor, or the like is formed over an organic resin with low heat resistance, it is difficult to apply a high temperature to the substrate in the manufacturing process. Here, a transistor including an oxide semiconductor can be favorably formed over an organic resin because a high-temperature manufacturing process is not essential.

Note that the organic resin may be used as a substrate included in the device, or the organic resin may be removed and another substrate may be bonded to the exposed surface of the layer to be peeled using an adhesive.

Alternatively, a metal layer may be provided between the manufacturing substrate and the organic resin, and current may be supplied to the metal layer to heat the metal layer, and separation may be performed at the interface between the metal layer and the organic resin.

There is no particular limitation on the layer formed as the layer to be peeled. For example, when the display panel illustrated in FIG. 4 is manufactured, the insulating layer 455, the transistor 470a, the transistor 470b, the display element 103, and the like are formed as the layer to be peeled 205, and the insulating layer 405 and the light shielding layer are formed as the layer to be peeled 225. 404, the transistor 420a, the transistor 420b, the coloring layer 181, the light-blocking layer 183, the display element 107, and the like may be formed.

The insulating layers 405 and 455 formed in contact with the separation layer are preferably formed using a silicon nitride film, a silicon oxynitride film, a silicon oxide film, a silicon nitride oxide film, or the like by a single layer or a multilayer.

The insulating layer can be formed by a sputtering method, a plasma CVD method, a coating method, a printing method, or the like. For example, by forming the insulating layer at a film formation temperature of 250 ° C. to 400 ° C. by a plasma CVD method. It can be made into a dense and very high moisture-proof film. Note that the thickness of the insulating layer is preferably 10 nm to 3000 nm, and more preferably 200 nm to 1500 nm.

Next, the manufacturing substrate 201 and the manufacturing substrate 221 are attached to each other with the adhesive layer 207 so that the surfaces on which the layers to be peeled are opposed to each other, and the adhesive layer 207 is cured (FIG. 9C). ).

Note that the bonding of the manufacturing substrate 201 and the manufacturing substrate 221 is preferably performed in a reduced-pressure atmosphere.

Note that FIG. 9C illustrates the case where the size of the release layer 223 is different from that of the release layer 203; however, a release layer having the same size may be used as illustrated in FIG. 9D.

The adhesive layer 207 is disposed so as to overlap with the separation layer 203, the separation layer 205, the separation layer 225, and the separation layer 223. And it is preferable that the edge part of the contact bonding layer 207 is located inside the edge part of at least one of the peeling layer 203 or the peeling layer 223 (one to peel first). Accordingly, it is possible to suppress the manufacturing substrate 201 and the manufacturing substrate 221 from being in close contact with each other, and it is possible to suppress a decrease in yield of a subsequent peeling step.

For the adhesive layer 207, for example, various curable adhesives such as a UV curable adhesive, a reactive curable adhesive, a thermosetting adhesive, and an anaerobic adhesive can be used. Examples of these adhesives include epoxy resins, acrylic resins, silicone resins, phenol resins, polyimide resins, imide resins, PVC (polyvinyl chloride) resins, PVB (polyvinyl butyral) resins, EVA (ethylene vinyl acetate) resins, and the like. In particular, a material with low moisture permeability such as an epoxy resin is preferable. As the adhesive, it is preferable to use a material having low fluidity so that it can be disposed only in a desired region. For example, an adhesive sheet, an adhesive sheet, a sheet-like or film-like adhesive may be used. For example, an OCA (Optical Clear Adhesive) film can be suitably used.

The adhesive may have adhesiveness before bonding, and may exhibit adhesiveness by heating or light irradiation after bonding.

Further, the resin may contain a desiccant. For example, a substance that adsorbs moisture by chemical adsorption, such as an alkaline earth metal oxide (such as calcium oxide or barium oxide), can be used. Alternatively, a substance that adsorbs moisture by physical adsorption, such as zeolite or silica gel, may be used. When a desiccant is contained, it is preferable because deterioration of the functional element due to intrusion of moisture in the atmosphere can be suppressed and the reliability of the apparatus is improved.

Next, a separation starting point is formed by laser light irradiation (FIGS. 10A and 10B).

The manufacturing substrate 201 and the manufacturing substrate 221 may be separated from each other. When the size of the release layer is different, the release layer may be peeled off from the substrate on which the large release layer is formed, or may be peeled off from the substrate on which the small release layer is formed. In the case where an element such as a semiconductor element, a light-emitting element, or a display element is formed over only one substrate, the element may be separated from the substrate on which the element is formed or may be separated from the other substrate. Here, an example in which the manufacturing substrate 201 is peeled first is shown.

The laser light is applied to a region where the cured adhesive layer 207, the layer to be peeled 205, and the peeling layer 203 overlap (see arrow P1 in FIG. 10A).

By removing a part of the first layer, a separation starting point can be formed (see a region surrounded by a dotted line in FIG. 10B). At this time, not only the first layer but also other layers of the layer to be peeled 205, or part of the peeling layer 203 and the adhesive layer 207 may be removed.

The laser light is preferably irradiated from the substrate side provided with a release layer to be peeled off. In the case of irradiating the region where the separation layer 203 and the separation layer 223 overlap with each other, by selectively cracking only the layer to be separated 205 of the layer to be separated 205 and the layer to be separated 225, the formation substrate 201 and The peeling layer 203 can be peeled (see a region surrounded by a dotted line in FIG. 10B. Here, an example in which part of each layer included in the peeled layer 205 is removed is shown).

Then, the layer to be peeled 205 and the manufacturing substrate 201 are separated from the starting point of peeling formed (FIGS. 10C and 10D). Accordingly, the layer to be peeled 205 can be transferred from the manufacturing substrate 201 to the manufacturing substrate 221. Note that the adhesive layer 207 formed outside the separation starting point remains on at least one of the manufacturing substrate 201 side and the manufacturing substrate 221. FIGS. 10C and 10D show examples that remain on both sides, but the present invention is not limited to this.

For example, the layer to be peeled and the manufacturing substrate 201 may be separated from the starting point of peeling by a physical force (a process of peeling with a human hand or a jig, a process of separating while rotating a roller, or the like).

Alternatively, the manufacturing substrate 201 and the layer to be peeled may be separated by penetrating a liquid such as water into the interface between the peeling layer 203 and the layer to be peeled. Separation can be easily achieved by the liquid penetrating between the peeling layer 203 and the peeled layer by capillary action. In addition, static electricity generated at the time of peeling can be prevented from adversely affecting the functional elements included in the layer to be peeled (for example, the semiconductor element is destroyed by static electricity).

Next, the exposed layer to be peeled 205 and the substrate 231 are attached to each other using the adhesive layer 233, and the adhesive layer 233 is cured (FIG. 11A).

Note that the layer to be peeled 205 and the substrate 231 are preferably attached in a reduced pressure atmosphere.

Next, a separation starting point is formed by laser light irradiation (FIGS. 11B and 11C).

The laser light is applied to a region where the cured adhesive layer 233, the layer to be peeled 225, and the peeling layer 223 overlap (see arrow P2 in FIG. 11B). By removing a part of the first layer, a peeling start point can be formed (see a region surrounded by a dotted line in FIG. 11C. Here, an example of removing a part of each layer constituting the layer to be peeled 225) Is shown.) At this time, not only the first layer but also other layers of the layer to be peeled 225, a part of the peeling layer 223, and the adhesive layer 233 may be removed.

The laser light is preferably irradiated from the manufacturing substrate 221 side provided with the separation layer 223.

Then, the layer to be peeled 225 and the manufacturing substrate 221 are separated from the starting point of the peeling (FIG. 11D). Accordingly, the layer to be peeled 205 and the layer to be peeled 225 can be transferred to the substrate 231. Note that the adhesive layer 233 formed outside the separation starting point remains on at least one of the manufacturing substrate 221 side and the substrate 231. Although FIG. 11D shows an example of remaining on both sides, the present invention is not limited to this.

In the method for manufacturing a display panel of one embodiment of the present invention described above, after a pair of manufacturing substrates each provided with a peeling layer and a layer to be peeled are bonded together, a starting point of peeling is formed by laser light irradiation. Peeling is performed after each peeling layer and the peeled layer are easily peeled. Thereby, the yield of a peeling process can be improved.

In addition, a pair of manufacturing substrates each having a layer to be peeled can be attached in advance, and then the substrates constituting the device to be manufactured can be attached by peeling. Therefore, when the layers to be peeled are bonded to each other, manufacturing substrates having low flexibility can be bonded to each other, and the alignment accuracy of the bonding can be improved as compared to the case where the flexible substrates are bonded to each other. it can.

Note that as illustrated in FIG. 12A, the end portion of the layer to be peeled 205 to be peeled is preferably formed so as to be located inside the end portion of the peeling layer 203. Thereby, the yield of a peeling process can be made high. When there are a plurality of layers to be peeled 205 to be peeled, a peeling layer 203 may be provided for each layer to be peeled 205 as shown in FIG. 12B, or 1 as shown in FIG. A plurality of layers to be peeled 205 may be provided over one peeling layer 203.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 4)
In this embodiment, an oxide semiconductor that can be used for the display panel or the like of one embodiment of the present invention will be described with reference to FIGS.

<Structure of oxide semiconductor>
Hereinafter, the structure of the oxide semiconductor is described.

An oxide semiconductor is classified into a non-single-crystal oxide semiconductor and a single-crystal oxide semiconductor, for example. Alternatively, an oxide semiconductor is classified into, for example, a crystalline oxide semiconductor and an amorphous oxide semiconductor.

Note that examples of the non-single-crystal oxide semiconductor include a CAAC-OS (C Axis Crystallized Oxide Semiconductor), a polycrystalline oxide semiconductor, a microcrystalline oxide semiconductor, and an amorphous oxide semiconductor. As a crystalline oxide semiconductor, a single crystal oxide semiconductor, a CAAC-OS, a polycrystalline oxide semiconductor, a microcrystalline oxide semiconductor, or the like can be given.

First, the CAAC-OS will be described.

The CAAC-OS is one of oxide semiconductors having a plurality of c-axis aligned crystal parts (also referred to as pellets).

A plurality of pellets can be confirmed by observing a bright field image of CAAC-OS and a combined analysis image (also referred to as a high-resolution TEM image) of a CAAC-OS with a transmission electron microscope (TEM: Transmission Electron Microscope). . On the other hand, a clear boundary between pellets, that is, a crystal grain boundary (also referred to as a grain boundary) cannot be confirmed even by a high-resolution TEM image. Therefore, it can be said that the CAAC-OS does not easily lower the electron mobility due to the crystal grain boundary.

For example, as illustrated in FIG. 13A, a high-resolution TEM image of a cross section of the CAAC-OS is observed from a direction substantially parallel to the sample surface. Here, a TEM image is observed using a spherical aberration correction function. In the following, a high-resolution TEM image using the spherical aberration correction function is particularly referred to as a Cs-corrected high-resolution TEM image. In addition, acquisition of a Cs correction | amendment high resolution TEM image can be performed by JEOL Co., Ltd. atomic resolution analytical electron microscope JEM-ARM200F etc., for example.

FIG. 13B shows a Cs-corrected high-resolution TEM image obtained by enlarging the region (1) in FIG. FIG. 13B shows that metal atoms are arranged in a layered manner in a pellet. Each layer of metal atoms has a shape that reflects unevenness of a surface (also referred to as a formation surface) or an upper surface on which a CAAC-OS film is formed, and is arranged in parallel with the formation surface or the upper surface of the CAAC-OS.

In FIG. 13B, the CAAC-OS has a characteristic atomic arrangement. FIG. 13C shows a characteristic atomic arrangement with auxiliary lines. From FIG. 13B and FIG. 13C, it can be seen that the size of one pellet is about 1 nm to 3 nm, and the size of the gap caused by the inclination between the pellet and the pellet is about 0.8 nm. Therefore, the pellet can also be referred to as a nanocrystal (nc).

Here, from the Cs-corrected high-resolution TEM image, when the arrangement of the CAAC-OS pellets 5100 on the substrate 5120 is schematically shown, a structure in which bricks or blocks are stacked is obtained (see FIG. 13D). . A portion where an inclination occurs between the pellets observed in FIG. 13C corresponds to a region 5161 illustrated in FIG.

For example, as shown in FIG. 14A, a Cs-corrected high-resolution TEM image of the plane of the CAAC-OS is observed from a direction substantially perpendicular to the sample surface. The Cs-corrected high-resolution TEM images obtained by enlarging the region (1), the region (2), and the region (3) in FIG. 14A are shown in FIGS. 14B, 14C, and 14D, respectively. Show. 14B, 14C, and 14D, it can be confirmed that the metal atoms are arranged in a triangular shape, a quadrangular shape, or a hexagonal shape in the pellet. However, there is no regularity in the arrangement of metal atoms between different pellets.

For example, when CAAC-OS including an InGaZnO ₄ crystal is subjected to structural analysis by an out-of-plane method using an X-ray diffraction (XRD) apparatus, as illustrated in FIG. In some cases, a peak appears when the diffraction angle (2θ) is around 31 °. Since this peak is attributed to the (009) plane of the InGaZnO ₄ crystal, the CAAC-OS crystal has c-axis orientation, and the c-axis is oriented in a direction substantially perpendicular to the formation surface or the top surface. It can be confirmed.

Note that in the structural analysis of the CAAC-OS including an InGaZnO ₄ crystal by an out-of-plane method, a peak may also appear when 2θ is around 36 ° in addition to the peak where 2θ is around 31 °. A peak at 2θ of around 36 ° indicates that a crystal having no c-axis alignment is included in part of the CAAC-OS. The CAAC-OS preferably has a peak at 2θ of around 31 ° and a peak at 2θ of around 36 °.

On the other hand, when structural analysis is performed on the CAAC-OS by an in-plane method in which X-rays are incident from a direction substantially perpendicular to the c-axis, a peak appears at 2θ of around 56 °. This peak is attributed to the (110) plane of the InGaZnO ₄ crystal. In the case of CAAC-OS, even when 2θ is fixed at around 56 ° and analysis (φ scan) is performed while rotating the sample with the normal vector of the sample surface as the axis (φ axis), FIG. A clear peak does not appear as shown. On the other hand, in the case of a single crystal oxide semiconductor of InGaZnO ₄ , when φ scan is performed with 2θ fixed at around 56 °, it belongs to a crystal plane equivalent to the (110) plane as shown in FIG. 6 peaks are observed. Therefore, from the structural analysis using XRD, the CAAC-OS can confirm that the orientation of the a-axis and the b-axis is irregular.

Next, a diffraction pattern (also referred to as a limited-field transmission electron diffraction pattern) when an electron beam with a probe diameter of 300 nm is incident on an In—Ga—Zn oxide that is a CAAC-OS from a direction parallel to the sample surface. ) Is shown in FIG. From FIG. 16A, for example, spots derived from the (009) plane of the InGaZnO ₄ crystal are confirmed. Therefore, electron diffraction shows that the pellets included in the CAAC-OS have c-axis alignment, and the c-axis is in a direction substantially perpendicular to the formation surface or the top surface. On the other hand, FIG. 16B shows a diffraction pattern obtained when an electron beam with a probe diameter of 300 nm is incident on the same sample from a direction perpendicular to the sample surface. From FIG. 16B, a ring-shaped diffraction pattern is confirmed. Therefore, electron diffraction shows that the a-axis and the b-axis of the pellet included in the CAAC-OS have no orientation. Note that the first ring in FIG. 16B is considered to originate from the (010) plane and the (100) plane of the InGaZnO ₄ crystal. In addition, it is considered that the second ring in FIG.

In this manner, since the c-axis of each pellet (nanocrystal) is oriented in a direction substantially perpendicular to the formation surface or the upper surface, an oxide semiconductor including CAAC-OS and CANC (C-Axis Aligned Nanocrystals). Can also be called.

The CAAC-OS is an oxide semiconductor with a low impurity concentration. The impurity is an element other than the main component of the oxide semiconductor, such as hydrogen, carbon, silicon, or a transition metal element. In particular, an element such as silicon, which has a stronger bonding force with oxygen than a metal element included in an oxide semiconductor, disturbs the atomic arrangement of the oxide semiconductor by depriving the oxide semiconductor of oxygen, thereby reducing crystallinity. It becomes a factor. In addition, heavy metals such as iron and nickel, argon, carbon dioxide, etc. have large atomic radii (or molecular radii), so if they are contained inside an oxide semiconductor, the atomic arrangement of the oxide semiconductor is disturbed and the crystallinity is lowered. It becomes a factor to make. Note that the impurity contained in the oxide semiconductor might serve as a carrier trap or a carrier generation source.

A CAAC-OS is an oxide semiconductor with a low density of defect states. For example, oxygen vacancies in an oxide semiconductor can serve as a carrier trap or a carrier generation source by capturing hydrogen.

In addition, a transistor using a CAAC-OS has little change in electrical characteristics due to irradiation with visible light or ultraviolet light.

Next, a microcrystalline oxide semiconductor will be described.

A microcrystalline oxide semiconductor has a region where a crystal part can be confirmed and a region where a clear crystal part cannot be confirmed in a high-resolution TEM image. In most cases, a crystal part in the microcrystalline oxide semiconductor has a size of 1 nm to 100 nm, or 1 nm to 10 nm. In particular, an oxide semiconductor including a nanocrystal that is a microcrystal of 1 nm to 10 nm, or 1 nm to 3 nm is referred to as an nc-OS (nanocrystalline Oxide Semiconductor). In addition, for example, the nc-OS may not clearly confirm the crystal grain boundary in a high-resolution TEM image. Note that the nanocrystal may have the same origin as the pellet in the CAAC-OS. Therefore, the crystal part of nc-OS is sometimes referred to as a pellet below.

The nc-OS has periodicity in atomic arrangement in a minute region (for example, a region of 1 nm to 10 nm, particularly a region of 1 nm to 3 nm). In addition, the nc-OS has no regularity in crystal orientation between different pellets. Therefore, orientation is not seen in the whole film. Therefore, the nc-OS may not be distinguished from an amorphous oxide semiconductor depending on an analysis method. For example, when structural analysis is performed on the nc-OS using an XRD apparatus using X-rays having a diameter larger than that of the pellet, a peak indicating a crystal plane is not detected in the analysis by the out-of-plane method. Further, when electron diffraction (also referred to as limited-field electron diffraction) using an electron beam with a probe diameter (for example, 50 nm or more) larger than the pellet is performed on the nc-OS, a diffraction pattern such as a halo pattern is observed. . On the other hand, when nanobeam electron diffraction is performed on the nc-OS using an electron beam having a probe diameter that is close to the pellet size or smaller than the pellet size, spots are observed. Further, when nanobeam electron diffraction is performed on the nc-OS, a region with high luminance may be observed like a circle (in a ring shape). Further, when nanobeam electron diffraction is performed on the nc-OS, a plurality of spots may be observed in the ring-shaped region.

In this manner, since the crystal orientation of each pellet (nanocrystal) does not have regularity, the nc-OS can also be referred to as an oxide semiconductor having NANC (Non-Aligned nanocrystals).

The nc-OS is an oxide semiconductor that has higher regularity than an amorphous oxide semiconductor. Therefore, the nc-OS has a lower density of defect states than an amorphous oxide semiconductor. Note that the nc-OS does not have regularity in crystal orientation between different pellets. Therefore, the nc-OS has a higher density of defect states than the CAAC-OS.

Next, an amorphous oxide semiconductor will be described.

An amorphous oxide semiconductor is an oxide semiconductor in which atomic arrangement in a film is irregular and does not have a crystal part. An example is an oxide semiconductor having an amorphous state such as quartz.

In an amorphous oxide semiconductor, a crystal part cannot be confirmed in a high-resolution TEM image.

When structural analysis using an XRD apparatus is performed on an amorphous oxide semiconductor, a peak indicating a crystal plane is not detected by analysis using an out-of-plane method. In addition, when electron diffraction is performed on an amorphous oxide semiconductor, a halo pattern is observed. Further, when nanobeam electron diffraction is performed on an amorphous oxide semiconductor, no spot is observed and a halo pattern is observed.

Various views have been presented regarding the amorphous structure. For example, a structure having no order in the atomic arrangement may be referred to as a complete amorphous structure. In addition, a structure having ordering up to the nearest interatomic distance or the distance between second adjacent atoms and having no long-range ordering may be referred to as an amorphous structure. Therefore, according to the strictest definition, an oxide semiconductor having order in the atomic arrangement cannot be called an amorphous oxide semiconductor. At least an oxide semiconductor having long-range order cannot be called an amorphous oxide semiconductor. Therefore, for example, the CAAC-OS and the nc-OS cannot be referred to as an amorphous oxide semiconductor or a completely amorphous oxide semiconductor because of having a crystal part.

Note that an oxide semiconductor may have a structure exhibiting physical properties between the nc-OS and the amorphous oxide semiconductor. An oxide semiconductor having such a structure is particularly referred to as an amorphous-like oxide semiconductor (a-like OS).

In the a-like OS, a void (also referred to as a void) may be observed in a high-resolution TEM image. Moreover, in a high-resolution TEM image, it has the area | region which can confirm a crystal part clearly, and the area | region which cannot confirm a crystal part.

Hereinafter, a difference in the influence of electron irradiation depending on the structure of the oxide semiconductor will be described.

An a-like OS, an nc-OS, and a CAAC-OS are prepared. Each sample is an In—Ga—Zn oxide.

First, a high-resolution cross-sectional TEM image of each sample is acquired. It can be seen from the high-resolution cross-sectional TEM image that each sample has a crystal part.

Further, the size of the crystal part of each sample is measured. FIG. 17 is an example in which the change in average size of the crystal parts (from 22 to 45) of each sample was investigated. From FIG. 17, it can be seen that in the a-like OS, the crystal part becomes larger according to the cumulative dose of electrons. Specifically, as shown by (1) in FIG. 17, the cumulative irradiation amount of the crystal part (also referred to as initial nucleus) which was about 1.2 nm in the initial observation by TEM is 4.2. It can be seen that the film grows to a size of about 2.6 nm at × 10 ⁸ e ⁻ / nm ² . On the other hand, the nc-OS and the CAAC-OS have a crystal part in a range from the start of electron irradiation to the cumulative electron dose of 4.2 × 10 ⁸ e ⁻ / nm ² regardless of the cumulative electron dose. It can be seen that there is no change in the size of. Specifically, as shown by (2) in FIG. 17, it can be seen that the size of the crystal part is about 1.4 nm regardless of the progress of observation by TEM. Further, as indicated by (3) in FIG. 17, it can be seen that the size of the crystal part is about 2.1 nm regardless of the progress of observation by TEM.

As described above, the a-like OS may be crystallized due to a small amount of electron irradiation as observed by a TEM, and a crystal part may be grown. On the other hand, when the nc-OS and the CAAC-OS are high-quality, it can be seen that crystallization due to a small amount of electron irradiation comparable to that observed with a TEM is hardly observed.

Note that the crystal part size of the a-like OS and the nc-OS can be measured using high-resolution TEM images. For example, a crystal of InGaZnO ₄ has a layered structure, and two Ga—Zn—O layers are provided between In—O layers. The unit cell of InGaZnO ₄ crystal has a structure in which a total of nine layers including three In—O layers and six Ga—Zn—O layers are stacked in the c-axis direction. Therefore, the distance between these adjacent layers is approximately the same as the lattice spacing (also referred to as d value) of the (009) plane, and the value is determined to be 0.29 nm from crystal structure analysis. Therefore, paying attention to the lattice fringes in the high-resolution TEM image, each lattice fringe corresponds to the ab plane of the InGaZnO ₄ crystal in a portion where the interval between the lattice fringes is 0.28 nm or more and 0.30 nm or less.

An oxide semiconductor may have a different density for each structure. For example, if the composition of a certain oxide semiconductor is known, the structure of the oxide semiconductor can be estimated by comparing with the density of a single crystal having the same composition as the composition. For example, the density of the a-like OS is 78.6% or more and less than 92.3% with respect to the density of the single crystal. For example, the density of the nc-OS and the density of the CAAC-OS are 92.3% or more and less than 100% with respect to the density of the single crystal. Note that it is difficult to form an oxide semiconductor whose density is lower than 78% with respect to that of a single crystal.

The above will be described using a specific example. For example, in an oxide semiconductor satisfying In: Ga: Zn = 1: 1: 1 [atomic ratio], the density of single crystal InGaZnO ₄ having a rhombohedral structure is 6.357 g / cm ³ . Thus, for example, in an oxide semiconductor that satisfies In: Ga: Zn = 1: 1: 1 [atomic ratio], the density of a-like OS is 5.0 g / cm ³ or more and less than 5.9 g / cm ^3. . For example, in the oxide semiconductor satisfying In: Ga: Zn = 1: 1: 1 [atomic ratio], the density of the nc-OS and the density of the CAAC-OS are 5.9 g / cm ³ or more and 6.3 g / cm. less than cm ³ .

Note that there may be no single crystal having the same composition. In that case, a density corresponding to a single crystal having a desired composition can be calculated by combining single crystals having different compositions at an arbitrary ratio. What is necessary is just to calculate the density of the single crystal of a desired composition using a weighted average with respect to the ratio which combines the single crystal from which a composition differs. However, the density is preferably calculated by combining as few kinds of single crystals as possible.

Note that the oxide semiconductor may be a stacked film including two or more of an amorphous oxide semiconductor, an a-like OS, a microcrystalline oxide semiconductor, and a CAAC-OS, for example.

An oxide semiconductor with a low impurity concentration and a low defect state density (low oxygen vacancies) can have a low carrier density. Therefore, such an oxide semiconductor is referred to as a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. The CAAC-OS and the nc-OS have a lower impurity concentration and a lower density of defect states than the a-like OS and the amorphous oxide semiconductor. That is, it is likely to be a highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor. Therefore, a transistor using the CAAC-OS or the nc-OS rarely has electric characteristics (also referred to as normally-on) in which the threshold voltage is negative. A highly purified intrinsic or substantially highly purified intrinsic oxide semiconductor has few carrier traps. Therefore, a transistor including the CAAC-OS or the nc-OS has a small change in electrical characteristics and has high reliability. Note that the charge trapped in the carrier trap of the oxide semiconductor takes a long time to be released, and may behave as if it were a fixed charge. Therefore, a transistor including an oxide semiconductor with a high impurity concentration and a high density of defect states may have unstable electrical characteristics.

<Film formation model>
An example of a CAAC-OS and nc-OS film formation model is described below.

FIG. 18A is a schematic view of a deposition chamber in which a CAAC-OS is deposited by a sputtering method.

The target 5130 is bonded to the backing plate. A plurality of magnets are arranged at positions facing the target 5130 via the backing plate. A magnetic field is generated by the plurality of magnets. A sputtering method that uses a magnetic field to increase the deposition rate is called a magnetron sputtering method.

The target 5130 has a polycrystalline structure, and any one of the crystal grains includes a cleavage plane.

As an example, a cleavage plane of the target 5130 including an In—Ga—Zn oxide is described. FIG. 19A illustrates a structure of InGaZnO ₄ crystal included in the target 5130. Note that FIG. 19A illustrates a structure in the case where an InGaZnO ₄ crystal is observed from a direction parallel to the b-axis with the c-axis facing upward.

FIG. 19A shows that in two adjacent Ga—Zn—O layers, oxygen atoms in each layer are arranged at a short distance. And when an oxygen atom has a negative charge, two adjacent Ga—Zn—O layers repel each other. As a result, the InGaZnO ₄ crystal has a cleavage plane between two adjacent Ga—Zn—O layers.

The substrate 5120 is disposed so as to face the target 5130, and the distance d (also referred to as target-substrate distance (T-S distance)) is 0.01 m or more and 1 m or less, preferably 0.02 m or more and 0. .5m or less. The film forming chamber is mostly filled with a film forming gas (for example, oxygen, argon, or a mixed gas containing oxygen at a ratio of 5% by volume or more) and is 0.01 Pa or more and 100 Pa or less, preferably 0.1 Pa or more and 10 Pa or less. Controlled. Here, by applying a voltage of a certain level or higher to the target 5130, discharge starts and plasma is confirmed. Note that a high-density plasma region is formed in the vicinity of the target 5130 by a magnetic field. In the high-density plasma region, ions 5101 are generated by ionizing the deposition gas. The ions 5101 are, for example, oxygen cations (O ⁺ ), argon cations (Ar ⁺ ), and the like.

The ions 5101 are accelerated toward the target 5130 by the electric field and eventually collide with the target 5130. At this time, the pellet 5100a and the pellet 5100b, which are flat or pellet-like sputtered particles, are peeled off from the cleavage plane and knocked out. Note that the pellets 5100a and 5100b may be distorted in structure due to the impact of collision of the ions 5101.

The pellet 5100a is a flat or pellet-like sputtered particle having a triangular plane, for example, a regular triangular plane. The pellet 5100b is a flat or pellet-like sputtered particle having a hexagonal plane, for example, a regular hexagonal plane. Note that flat or pellet-like sputtered particles such as the pellet 5100a and the pellet 5100b are collectively referred to as a pellet 5100. The planar shape of the pellet 5100 is not limited to a triangle or a hexagon. For example, there are cases where a plurality of triangles are combined. For example, there may be a quadrangle (for example, a rhombus) in which two triangles (for example, regular triangles) are combined.

The thickness of the pellet 5100 is determined in accordance with the type of film forming gas. Although the reason will be described later, it is preferable to make the thickness of the pellet 5100 uniform. Moreover, it is more preferable that the sputtered particles are in the form of pellets with no thickness than in the form of thick dice. For example, the pellet 5100 has a thickness of 0.4 nm to 1 nm, preferably 0.6 nm to 0.8 nm. For example, the pellet 5100 has a width of 1 nm to 3 nm, preferably 1.2 nm to 2.5 nm. The pellet 5100 corresponds to the initial nucleus described in (1) in FIG. For example, in the case where an ion 5101 is caused to collide with a target 5130 including an In—Ga—Zn oxide, a Ga—Zn—O layer, an In—O layer, and a Ga—Zn—O layer are formed as shown in FIG. A pellet 5100 having three layers pops out. Note that FIG. 19C illustrates a structure in the case where the pellet 5100 is observed from a direction parallel to the c-axis. Therefore, the pellet 5100 can also be referred to as a nano-sized sandwich structure including two Ga—Zn—O layers (pan) and an In—O layer (tool).

The pellet 5100 may receive a charge when passing through the plasma, so that the side surface may be negatively or positively charged. The pellet 5100 has oxygen atoms on the side surfaces, and the oxygen atoms may be negatively charged. In this way, when the side surfaces are charged with the same polarity, charges are repelled and a flat plate shape can be maintained. Note that in the case where the CAAC-OS is an In—Ga—Zn oxide, an oxygen atom bonded to an indium atom may be negatively charged. Alternatively, oxygen atoms bonded to indium atoms, gallium atoms, or zinc atoms may be negatively charged. In addition, the pellet 5100 may grow by bonding with indium atoms, gallium atoms, zinc atoms, oxygen atoms, and the like when passing through plasma. The difference in size between (2) and (1) in FIG. 17 described above corresponds to the amount of growth in plasma. Here, when the substrate 5120 has a temperature of about room temperature, the pellet 5100 does not grow any more and thus becomes an nc-OS (see FIG. 18B). Since the film forming temperature is about room temperature, the nc-OS can be formed even when the substrate 5120 has a large area. Note that in order to grow the pellet 5100 in plasma, it is effective to increase the deposition power in the sputtering method. By increasing the deposition power, the structure of the pellet 5100 can be stabilized.

As shown in FIGS. 18A and 18B, for example, the pellet 5100 flies like a kite in the plasma and flutters up to the substrate 5120. Since the pellet 5100 is charged, a repulsive force is generated when a region where another pellet 5100 has already been deposited approaches. Here, a magnetic field (also referred to as a horizontal magnetic field) in a direction parallel to the upper surface of the substrate 5120 is generated on the upper surface of the substrate 5120. In addition, since a potential difference is applied between the substrate 5120 and the target 5130, a current flows from the substrate 5120 toward the target 5130. Therefore, the pellet 5100 receives a force (Lorentz force) on the upper surface of the substrate 5120 by the action of a magnetic field and a current. This can be understood by Fleming's left-hand rule.

The pellet 5100 has a larger mass than one atom. Therefore, in order to move the upper surface of the substrate 5120, it is important to apply some force from the outside. One of the forces may be a force generated by the action of a magnetic field and an electric current. Note that in order to increase the force applied to the pellet 5100, the magnetic field in the direction parallel to the upper surface of the substrate 5120 is 10 G or more, preferably 20 G or more, more preferably 30 G or more, more preferably 50 G or more. It is good to provide the area | region which becomes. Alternatively, on the upper surface of the substrate 5120, the magnetic field in the direction parallel to the upper surface of the substrate 5120 is 1.5 times or more, preferably 2 times or more, more preferably 3 times or more, the magnetic field in the direction perpendicular to the upper surface of the substrate 5120. More preferably, a region that is five times or more is provided.

At this time, the direction of the horizontal magnetic field on the upper surface of the substrate 5120 continues to change as the magnet and the substrate 5120 move or rotate relative to each other. Therefore, on the upper surface of the substrate 5120, the pellet 5100 receives forces in various directions and can move in various directions.

As shown in FIG. 18A, when the substrate 5120 is heated, the resistance due to friction or the like is small between the pellet 5100 and the substrate 5120. As a result, the pellet 5100 moves so as to glide over the upper surface of the substrate 5120. The movement of the pellet 5100 occurs in a state where the flat plate surface faces the substrate 5120. Thereafter, when reaching the side surfaces of the other pellets 5100 already deposited, the side surfaces are bonded to each other. At this time, oxygen atoms on the side surfaces of the pellet 5100 are desorbed. Since the released oxygen atom may fill an oxygen vacancy in the CAAC-OS, the CAAC-OS has a low density of defect states. Note that the temperature of the upper surface of the substrate 5120 may be, for example, 100 ° C. or higher and lower than 500 ° C., 150 ° C. or higher and lower than 450 ° C., or 170 ° C. or higher and lower than 400 ° C. That is, the CAAC-OS can be formed even when the substrate 5120 has a large area.

Further, when the pellet 5100 is heated on the substrate 5120, atoms are rearranged, and structural distortion caused by the collision of the ions 5101 is reduced. The pellet 5100 whose strain is relaxed is substantially a single crystal. Since the pellet 5100 is substantially a single crystal, even if the pellets 5100 are heated after being bonded to each other, the pellet 5100 itself hardly expands or contracts. Accordingly, the gaps between the pellets 5100 are widened, so that defects such as crystal grain boundaries are not formed and crevasses are not formed.

In the CAAC-OS, single crystal oxide semiconductors are not formed as a single plate, but an aggregate of pellets 5100 (nanocrystals) is arranged such that bricks or blocks are stacked. Further, there is no crystal grain boundary between them. Therefore, even when deformation such as shrinkage occurs in the CAAC-OS due to heating during film formation, heating after film formation, bending, or the like, local stress can be relieved or distortion can be released. Therefore, the structure is suitable for a flexible semiconductor device. Note that the nc-OS has an arrangement in which pellets 5100 (nanocrystals) are stacked randomly.

When the target is sputtered with ions, not only pellets but also zinc oxide or the like may jump out. Since zinc oxide is lighter than the pellet, it reaches the upper surface of the substrate 5120 first. Then, a zinc oxide layer 5102 having a thickness of 0.1 nm to 10 nm, 0.2 nm to 5 nm, or 0.5 nm to 2 nm is formed. FIG. 20 shows a schematic cross-sectional view.

As shown in FIG. 20A, pellets 5105a and 5105b are deposited over the zinc oxide layer 5102. Here, the pellet 5105a and the pellet 5105b are arranged so that the side surfaces thereof are in contact with each other. In addition, the pellet 5105c moves so as to slide on the pellet 5105b after being deposited on the pellet 5105b. Further, on another side surface of the pellet 5105a, a plurality of particles 5103 jumping out of the target together with zinc oxide are crystallized by heating the substrate 5120 to form a region 5105a1. Note that the plurality of particles 5103 may contain oxygen, zinc, indium, gallium, or the like.

Then, as illustrated in FIG. 20B, the region 5105a1 is assimilated with the pellet 5105a to become a pellet 5105a2. In addition, the pellet 5105c is arranged so that its side surface is in contact with another side surface of the pellet 5105b.

Next, as illustrated in FIG. 20C, after the pellet 5105d is further deposited on the pellet 5105a2 and the pellet 5105b, the pellet 5105d moves so as to slide on the pellet 5105a2 and the pellet 5105b. Further, the pellet 5105e moves so as to slide on the zinc oxide layer 5102 toward another side surface of the pellet 5105c.

Then, as illustrated in FIG. 20D, the pellet 5105d is disposed so that the side surface thereof is in contact with the side surface of the pellet 5105a2. In addition, the pellet 5105e is arranged so that its side surface is in contact with another side surface of the pellet 5105c. In addition, on another side surface of the pellet 5105d, a plurality of particles 5103 jumping out of the target together with zinc oxide are crystallized by heating the substrate 5120, so that a region 5105d1 is formed.

As described above, the deposited pellets are arranged so as to be in contact with each other, and growth occurs on the side surfaces of the pellets, whereby a CAAC-OS is formed over the substrate 5120. Therefore, each CAAC-OS has a larger pellet than the nc-OS. The difference in size between (3) and (2) in FIG. 17 corresponds to the amount of growth after deposition.

In addition, when the gap between the pellets 5100 is extremely small, one large pellet may be formed. Large pellets have a single crystal structure. For example, the size of a large pellet may be 10 nm to 200 nm, 15 nm to 100 nm, or 20 nm to 50 nm when viewed from above. Therefore, when the channel formation region of the transistor is smaller than a large pellet, a region having a single crystal structure can be used as the channel formation region. In addition, when the pellet is large, a region having a single crystal structure can be used as a channel formation region, a source region, and a drain region of the transistor in some cases.

In this manner, when the channel formation region or the like of the transistor is formed in a region having a single crystal structure, the frequency characteristics of the transistor can be improved.

It is considered that the pellet 5100 is deposited on the substrate 5120 by the above model. Therefore, it can be seen that, unlike epitaxial growth, a CAAC-OS film can be formed even when a formation surface does not have a crystal structure. For example, the CAAC-OS can be formed even if the top surface (formation surface) of the substrate 5120 has an amorphous structure (eg, amorphous silicon oxide).

In addition, in the CAAC-OS, even when the top surface of the substrate 5120 which is a formation surface is uneven, it can be seen that the pellets 5100 are arranged along the shape. For example, when the upper surface of the substrate 5120 is flat at the atomic level, the pellet 5100 is juxtaposed with the flat plate surface parallel to the ab surface facing downward. When the thickness of the pellet 5100 is uniform, a layer having a uniform and flat thickness and high crystallinity is formed. The CAAC-OS can be obtained by stacking n layers (n is a natural number).

On the other hand, even when the top surface of the substrate 5120 is uneven, the CAAC-OS has a structure in which n layers (n is a natural number) of layers in which pellets 5100 are arranged along the unevenness are stacked. Since the substrate 5120 has unevenness, the CAAC-OS might easily have a gap between the pellets 5100. However, the intermolecular force works between the pellets 5100, and even if there are irregularities, the gaps between the pellets are arranged to be as small as possible. Therefore, a CAAC-OS having high crystallinity can be obtained even when there is unevenness.

Therefore, the CAAC-OS does not require laser crystallization and can form a uniform film even on a large-area glass substrate or the like.

Since a CAAC-OS film is formed using such a model, it is preferable that the sputtered particles have a thin pellet shape. Note that in the case where the sputtered particles have a thick dice shape, the surface directed onto the substrate 5120 is not constant, and the thickness and crystal orientation may not be uniform.

With the deposition model described above, a CAAC-OS having high crystallinity can be obtained even on a formation surface having an amorphous structure.

This embodiment can be combined with any of the other embodiments as appropriate.

(Embodiment 5)
In this embodiment, electronic devices and lighting devices of one embodiment of the present invention will be described with reference to FIGS.

An electronic device or a lighting device having a curved surface, high visibility, and low power consumption can be manufactured using the display panel or the like of one embodiment of the present invention. In addition, with the use of the display panel or the like of one embodiment of the present invention, an electronic device or a lighting device which has flexibility, high visibility, and low power consumption can be manufactured.

Examples of the electronic device include a television device (also referred to as a television or a television receiver), a monitor for a computer, a digital camera, a digital video camera, a digital photo frame, a mobile phone (also referred to as a mobile phone or a mobile phone device). ), Large game machines such as portable game machines, portable information terminals, sound reproducing devices, and pachinko machines.

In addition, since the electronic device or the lighting device of one embodiment of the present invention has flexibility, it can be incorporated along an inner wall or an outer wall of a house or a building, or a curved surface of an interior or exterior of an automobile.

The electronic device of one embodiment of the present invention may include a secondary battery, and it is preferable that the secondary battery can be charged using non-contact power transmission.

Secondary batteries include, for example, lithium ion secondary batteries such as lithium polymer batteries (lithium ion polymer batteries) using a gel electrolyte, lithium ion batteries, nickel metal hydride batteries, nickel-cadmium batteries, organic radical batteries, lead storage batteries, air batteries A secondary battery, a nickel zinc battery, a silver zinc battery, etc. are mentioned.

The electronic device of one embodiment of the present invention may include an antenna. By receiving a signal with an antenna, video, information, and the like can be displayed on the display unit. Further, when the electronic device has a secondary battery, the antenna may be used for non-contact power transmission.

FIGS. 21A, 21B, 21C1, 21D, and 21E each show an example of an electronic device having a curved display portion 7000. FIG. The display portion 7000 is provided with a curved display surface, and can perform display along the curved display surface. Note that the display portion 7000 may have flexibility.

The display portion 7000 is manufactured using the display panel or the like of one embodiment of the present invention.

According to one embodiment of the present invention, an electronic device including a curved display portion, high visibility, and low power consumption can be provided.

FIG. 21A illustrates an example of a mobile phone. A cellular phone 7100 includes a housing 7101, a display portion 7000, operation buttons 7103, an external connection port 7104, a speaker 7105, a microphone 7106, and the like.

A mobile phone 7100 illustrated in FIG. 21A includes a touch sensor in the display portion 7000. All operations such as making a call or inputting characters can be performed by touching the display portion 7000 with a finger or a stylus.

Further, by operating the operation button 7103, the power ON / OFF operation and the type of image displayed on the display portion 7000 can be switched. For example, the mail creation screen can be switched to the main menu screen.

FIG. 21B illustrates an example of a television set. In the television device 7200, a display portion 7000 is incorporated in a housing 7201. Here, a structure in which the housing 7201 is supported by a stand 7203 is shown.

The television device 7200 illustrated in FIG. 21B can be operated with an operation switch included in the housing 7201 or a separate remote controller 7211. Alternatively, the display unit 7000 may be provided with a touch sensor, and may be operated by touching the display unit 7000 with a finger or the like. The remote controller 7211 may include a display unit that displays information output from the remote controller 7111. Channels and volume can be operated with an operation key or a touch panel included in the remote controller 7211, and an image displayed on the display portion 7000 can be operated.

Note that the television device 7200 is provided with a receiver, a modem, and the like. A general television broadcast can be received by the receiver. In addition, by connecting to a wired or wireless communication network via a modem, information communication is performed in one direction (from the sender to the receiver) or in two directions (between the sender and the receiver or between the receivers). It is also possible.

Examples of portable information terminals are shown in FIGS. 21C1, C2, D, and E. Each portable information terminal includes a housing 7301 and a display portion 7000. Furthermore, an operation button, an external connection port, a speaker, a microphone, an antenna, a battery, or the like may be included. The display unit 7000 includes a touch sensor. The portable information terminal can be operated by touching the display portion 7000 with a finger or a stylus.

FIG. 21C1 is a perspective view of the portable information terminal 7300, and FIG. 21C2 is a top view of the portable information terminal 7300. FIG. 21D is a perspective view of portable information terminal 7310. FIG. 21E is a perspective view of the portable information terminal 7320.

The portable information terminal exemplified in this embodiment has one or a plurality of functions selected from, for example, a telephone, a notebook, an information browsing device, or the like. Specifically, each can be used as a smartphone. The portable information terminal exemplified in this embodiment can execute various applications such as mobile phone, e-mail, text browsing and creation, music playback, Internet communication, and computer games.

The portable information terminal 7300, the portable information terminal 7310, and the portable information terminal 7320 can display characters and image information on a plurality of surfaces. For example, as shown in FIGS. 21C1 and 21D, three operation buttons 7302 can be displayed on one surface, and information 7303 indicated by a rectangle can be displayed on the other surface. FIGS. 21C1 and 21C2 illustrate an example in which information is displayed on the upper side of the portable information terminal, and FIG. 21D illustrates an example in which information is displayed on the side of the portable information terminal. In addition, information may be displayed on three or more surfaces of the portable information terminal. FIG. 21E illustrates an example in which information 7304, information 7305, and information 7306 are displayed on different surfaces.

Examples of information include SNS (social networking service) notifications, displays that notify incoming calls such as e-mails and telephone calls, e-mail titles or sender names, date and time, time, battery level, antenna There is the strength of reception. Alternatively, an operation button, an icon, or the like may be displayed instead of the information at a position where the information is displayed.

For example, the user of the portable information terminal 7300 can check the display (information 7303 in this case) in a state where the portable information terminal 7300 is stored in the chest pocket of clothes.

Specifically, the telephone number or name of the caller of the incoming call is displayed at a position where the mobile information terminal 7300 can be observed from above. The user can check the display and determine whether to receive a call without taking out the portable information terminal 7300 from the pocket.

FIGS. 21F to 21H illustrate an example of a lighting device having a curved light emitting portion.

The light-emitting portion included in each lighting device illustrated in FIGS. 21F to 21H is manufactured using the display panel or the like of one embodiment of the present invention.

According to one embodiment of the present invention, a lighting device including a curved light-emitting portion, high visibility, and low power consumption can be provided.

A lighting device 7400 illustrated in FIG. 21F includes a light-emitting portion 7402 having a wavy light-emitting surface. Therefore, the lighting device has high design.

A light emitting portion 7412 included in the lighting device 7410 illustrated in FIG. 21G has a structure in which two light emitting portions curved in a convex shape are arranged symmetrically. Therefore, all directions can be illuminated around the lighting device 7410.

A lighting device 7420 illustrated in FIG. 21H includes a light-emitting portion 7422 curved in a concave shape. Therefore, the light emitted from the light emitting unit 7422 is condensed on the front surface of the lighting device 7420, which is suitable for brightly illuminating a specific range. In addition, with such a configuration, there is an effect that it is difficult to make a shadow.

In addition, each light emitting unit included in the lighting device 7400, the lighting device 7410, and the lighting device 7420 may have flexibility. The light emitting portion may be fixed by a member such as a plastic member or a movable frame, and the light emitting surface of the light emitting portion may be freely bent according to the application.

Each of the lighting device 7400, the lighting device 7410, and the lighting device 7420 includes a base portion 7401 including an operation switch 7403 and a light emitting portion supported by the base portion 7401.

Note that although the lighting device in which the light emitting unit is supported by the base is illustrated here, a housing including the light emitting unit can be fixed to the ceiling or can be used to hang from the ceiling. Since the light emitting surface can be curved and used, the light emitting surface can be curved concavely to illuminate a specific area, or the light emitting surface can be curved convexly to illuminate the entire room.

FIGS. 22A1 to 22I each show an example of a portable information terminal including a flexible display portion 7001. FIG.

The display portion 7001 is manufactured using the display panel or the like of one embodiment of the present invention. For example, a display panel that can be bent with a curvature radius of 0.01 mm to 150 mm can be used. The display portion 7001 may include a touch sensor, and the portable information terminal can be operated by touching the display portion 7001 with a finger or the like.

According to one embodiment of the present invention, an electronic device including a flexible display portion, high visibility, and low power consumption can be provided.

FIG. 22A1 is a perspective view illustrating an example of a portable information terminal, and FIG. 9A2 is a side view illustrating an example of a portable information terminal. A portable information terminal 7500 includes a housing 7501, a display portion 7001, a drawer member 7502, operation buttons 7503, and the like.

A portable information terminal 7500 includes a flexible display portion 7001 wound in a roll shape in a housing 7501.

Further, the portable information terminal 7500 can receive a video signal by a built-in control unit, and can display the received video on the display unit 7001. In addition, the portable information terminal 7500 has a built-in battery. Further, a terminal portion for connecting a connector to the housing 7501 may be provided, and a video signal and power may be directly supplied from the outside by wire.

Further, operation buttons 7503 can be used to perform power ON / OFF operations, switching of displayed images, and the like. 22A1, 22A2, and 22B illustrate an example in which the operation button 7503 is disposed on the side surface of the portable information terminal 7500, the present invention is not limited to this, and the same surface as the display surface of the portable information terminal 7500 is used. (Front surface) or on the back surface.

FIG. 22B illustrates the portable information terminal 7500 in which the display portion 7001 is pulled out by a pull-out member 7502. In this state, an image can be displayed on the display portion 7001. Further, the portable information terminal 7500 displays differently between the state of FIG. 22A1 in which a part of the display portion 7001 is wound in a roll shape and the state of FIG. 22B in which the display portion 7001 is pulled out by the pullout member 7502. It is good also as composition which performs. For example, in the state of FIG. 22A1, power consumption of the portable information terminal 7500 can be reduced by hiding a portion of the display portion 7001 wound in a roll shape.

Note that a reinforcing frame may be provided on a side portion of the display portion 7001 in order to fix the display surface of the display portion 7001 so that the display surface becomes flat when the display portion 7001 is pulled out.

In addition to this configuration, a speaker may be provided in the housing, and audio may be output by an audio signal received together with the video signal.

FIGS. 22C to 22E show examples of portable information terminals that can be folded. In FIG. 22C, the portable information terminal is in the expanded state, in FIG. 22D, in the middle of changing from the expanded state or the folded state to the other, in FIG. 22E, in the folded state. 7600 is shown. The portable information terminal 7600 is excellent in portability in the folded state, and in the expanded state, the portable information terminal 7600 is excellent in listability due to a seamless wide display area.

The display portion 7001 is supported by three housings 7601 connected by a hinge 7602. By bending between the two housings 7601 through the hinge 7602, the portable information terminal 7600 can be reversibly deformed from a developed state to a folded state.

FIGS. 22F and 22G illustrate an example of a foldable portable information terminal. FIG. 22F illustrates the portable information terminal 7650 in a state where the display portion 7001 is folded so as to be on the outside, and FIG. 22G illustrates the portable information terminal 7650 in a state where the display portion 7001 is folded on the inside. The portable information terminal 7650 includes a display portion 7001 and a non-display portion 7651. When the portable information terminal 7650 is not used, the display portion 7001 can be folded so that the display portion 7001 is on the inner side, whereby the display portion 7001 can be prevented from being dirty or damaged.

FIG. 22H illustrates an example of a flexible portable information terminal. A portable information terminal 7700 includes a housing 7701 and a display portion 7001. Further, buttons 7703a and 7703b as input means, speakers 7704a and 7704b as sound output means, an external connection port 7705, a microphone 7706, and the like may be provided. In addition, the portable information terminal 7700 can be equipped with a flexible battery 7709. The battery 7709 may be disposed so as to overlap with the display portion 7001, for example.

The housing 7701, the display portion 7001, and the battery 7709 have flexibility. Therefore, it is easy to curve the portable information terminal 7700 into a desired shape or to twist the portable information terminal 7700. For example, the portable information terminal 7700 can be used by being folded so that the display portion 7001 is inside or outside. Alternatively, the portable information terminal 7700 can be used in a rolled state. In this manner, since the housing 7701 and the display portion 7001 can be freely deformed, the portable information terminal 7700 is hardly damaged even when it is dropped or an unintended external force is applied. There are advantages.

Further, since the portable information terminal 7700 is lightweight, it can be used by holding the top of the housing 7701 with a clip or the like and hanging it, or by fixing the housing 7701 to a wall surface with a magnet or the like. Can be used conveniently.

FIG. 22I illustrates an example of a wristwatch-type portable information terminal. A portable information terminal 7800 includes a band 7801, a display portion 7001, input / output terminals 7802, operation buttons 7803, and the like. The band 7801 has a function as a housing. Further, the portable information terminal 7800 can be equipped with a flexible battery 7805. The battery 7805 may be disposed so as to overlap with the display portion 7001 or the band 7801, for example.

The band 7801, the display portion 7001, and the battery 7805 are flexible. Therefore, it is easy to curve the portable information terminal 7800 into a desired shape.

The operation button 7803 can have various functions such as time setting, power on / off operation, wireless communication on / off operation, manner mode execution and release, and power saving mode execution and release. . For example, the function of the operation button 7803 can be freely set by an operation system incorporated in the portable information terminal 7800.

In addition, an application can be started by touching an icon 7804 displayed on the display portion 7001 with a finger or the like.

In addition, the portable information terminal 7800 can perform short-range wireless communication with a communication standard. For example, it is possible to talk hands-free by communicating with a headset capable of wireless communication.

Further, the portable information terminal 7800 may include an input / output terminal 7802. In the case of having the input / output terminal 7802, data can be directly exchanged with another information terminal via a connector. Charging can also be performed through the input / output terminal 7802. Note that the charging operation of the portable information terminal exemplified in this embodiment may be performed by non-contact power transmission without using an input / output terminal.

FIG. 23A illustrates the appearance of an automobile 9700. FIG. FIG. 23B illustrates a driver seat of the automobile 9700. The automobile 9700 includes a vehicle body 9701, wheels 9702, a dashboard 9703, lights 9704, and the like. The display panel of one embodiment of the present invention can be used for a display portion of an automobile 9700 or the like. For example, the display panel of one embodiment of the present invention can be provided in the display portion 9710 to the display portion 9715 illustrated in FIG.

A display portion 9710 and a display portion 9711 are display devices provided on the windshield of the automobile. By manufacturing at least part of the display panel of one embodiment of the present invention with a light-transmitting material, a display device in a so-called see-through state in which the opposite side can be seen can be obtained. If the display device is in the see-through state, the visibility is not hindered even when the automobile 9700 is driven. Thus, the display panel of one embodiment of the present invention can be provided on the windshield of the automobile 9700. Note that in the case where a transistor for driving the display device or the like is provided in the display device, a light-transmitting transistor such as an organic transistor using an organic semiconductor material or a transistor using an oxide semiconductor is preferably used. .

A display portion 9712 is a display device provided in the pillar portion. For example, the field of view blocked by the pillar can be complemented by displaying an image from the imaging means provided on the vehicle body on the display portion 9712. A display portion 9713 is a display device provided in the dashboard portion. For example, by displaying an image from an imaging unit provided on the vehicle body on the display portion 9713, the view blocked by the dashboard can be complemented. That is, by projecting an image from the imaging means provided outside the automobile, the blind spot can be compensated and safety can be improved. Also, by displaying a video that complements the invisible part, it is possible to confirm the safety more naturally and without a sense of incongruity.

FIG. 24 shows the interior of an automobile in which bench seats are used for the driver seat and the passenger seat. The display portion 9721 is a display device provided in the door portion. For example, the field of view blocked by the door can be complemented by displaying an image from an imaging unit provided on the vehicle body on the display portion 9721. The display portion 9722 is a display device provided on the handle. The display unit 9723 is a display device provided at the center of the seat surface of the bench seat. Note that the display device can be installed on a seating surface or a backrest portion, and the display device can be used as a seat heater using heat generated by the display device as a heat source.

The display portion 9714, the display portion 9715, or the display portion 9722 can provide various other information such as navigation information, a speedometer and a tachometer, a travel distance, an oil supply amount, a gear state, and an air conditioner setting. In addition, display items, layouts, and the like displayed on the display unit can be changed as appropriate according to the user's preference. Note that the above information can also be displayed on the display portion 9710 to the display portion 9713, the display portion 9721, and the display portion 9723. The display portions 9710 to 9715 and the display portions 9721 to 9723 can also be used as lighting devices. The display portions 9710 to 9715 and the display portions 9721 to 9723 can also be used as heating devices.

This embodiment can be combined with any of the other embodiments as appropriate.

100 Display panel 101 Substrate 102 Element region 102B Element region 102G Element region 102R Element region 103 Display element 105 Adhesive layer 105a Adhesive layer 105b Adhesive layer 107 Display element 109 Substrate 110 Display region 113 Element layer 117 Element layer 121 Transistor layer 131 Lower electrode 131B Lower electrode 131G Lower electrode 131R Lower electrode 132 Optical adjustment layer 133 EL layer 135 Upper electrode 141 Insulating layer 171 Electrode 173 Layer 174 containing liquid crystal 175 Electrode 181 Colored layer 181B Colored layer 181G Colored layer 181R Colored layer 183 Light-shielding layer 191 Transistor layer 200 Display device 201 Fabrication substrate 202 Drive circuit 203 Peel layer 205 Peel layer 207 Adhesive layer 213 Drive device 215 Detector 221 Fabrication substrate 223 Peel layer 225 Strip layer 31 Substrate 233 Adhesive layer 403 Adhesive layer 404 Light shielding layer 405 Insulating layer 406 Insulating layer 407 Insulating layer 409 Insulating layer 416 Insulating layer 416b Insulating layer 416c Insulating layer 420a Transistor 420b Transistor 421 Conducting layer 428 Insulating layer 436 Conducting layer 437 Conducting Layer 438 Conductive layer 439 Conductive layer 443 Connection body 445 FPC
451 Substrate 453 Adhesive layer 455 Insulating layer 457 Insulating layer 459 Insulating layer 461a Insulating layer 461b Insulating layer 462 Conductive layer 467 Insulating layer 470a Transistor 470b Transistor 471 Conductive layer 473 Capacitance element 474 Transistor 482 Conductive layer 483 Connector 485 FPC
879 Adhesive layer 880 Capacitance element 888 Substrate 889 Adhesive layer 891 FPC
892 Connector 893 Insulating layer 894 Conductive layer 895 Insulating layer 896 Insulating layer 897 Insulating layer 898 Adhesive layer 899 Substrate 5100 Pellet 5100a Pellet 5100b Pellet 5101 Ion 5102 Zinc oxide layer 5103 Particles 5105a Pellet 5105a1 Region 5105a2 Pellet 5105d Pellet 5105d Pellet 51051 Region 5105e Pellet 5120 Substrate 5130 Target 5161 Region 7000 Display unit 7001 Display unit 7100 Mobile phone 7101 Case 7103 Operation button 7104 External connection port 7105 Speaker 7106 Microphone 7111 Remote control device 7200 Television device 7201 Case 7203 Stand 7211 Remote control device 7300 Portable information terminal 7301 Housing 7302 Operation button 7303 Information 7304 Information 7305 Information 7306 Information 7310 Portable information terminal 7320 Portable information terminal 7400 Lighting device 7401 Base unit 7402 Light emitting unit 7403 Operation switch 7410 Lighting device 7412 Light emitting unit 7420 Lighting device 7422 Light emitting unit 7500 Portable information terminal 7501 Case 7502 Member 7503 Operation button 7600 Portable information terminal 7601 Housing 7602 Hinge 7650 Portable information terminal 7651 Non-display unit 7700 Portable information terminal 7701 Case 7703a Button 7703b Button 7704a Speaker 7704b Speaker 7705 External connection port 7706 Microphone 7709 Battery 7800 Portable information terminal 7801 Band 7802 Input / output terminal 7803 Operation button 7804 Icon 7805 Battery 9700 Car 9701 Body 9702 wheel 9703 dashboard 9704 light 9710 display unit 9711 display unit 9712 display unit 9713 display unit 9714 display unit 9715 display unit 9721 display unit 9722 display unit 9723 display unit

Claims (8)

A display panel having flexibility,
A first display element and a second display element;
The first display element has a first portion in which the first display element and the second display element overlap each other.
The first portion of the first display element has a function of emitting light to the second display element side,
The display panel, wherein the second display element has a portion whose light transmittance is variable. A display panel having flexibility,
A first substrate, a second substrate, a first adhesive layer, a first display element, and a second display element;
The adhesive layer is located between the first substrate and the second substrate;
The first display element is located between the first substrate and the adhesive layer,
The second display element is located between the second substrate and the adhesive layer,
The first display element includes a first electrode, a layer containing a light-emitting organic compound, and a second electrode,
The layer containing a light-emitting organic compound is located between the first electrode and the second electrode,
The second display element has a third electrode, a layer containing liquid crystal, and a fourth electrode.
The liquid crystal containing layer is located between the third electrode and the fourth electrode;
The first display element has a first portion in which the first display element and the second display element overlap each other.
The first portion of the first display element has a function of emitting light to the second display element side,
The display panel, wherein the second display element has a portion whose light transmittance is variable. In claim 2,
The first electrode is located between the first substrate and the second electrode,
The first electrode has a function of reflecting visible light,
The second electrode has a function of transmitting visible light,
The third electrode has a function of transmitting visible light,
The fourth electrode is a display panel having a function of transmitting visible light. In claim 2 or 3,
A second adhesive layer, a third adhesive layer, a first insulating layer, a second insulating layer, a first transistor, and a second transistor;
The first insulating layer is located between the first substrate and the first display element,
The second adhesive layer is located between the first substrate and the first insulating layer,
The second insulating layer is located between the second substrate and the second display element,
The third adhesive layer is located between the second substrate and the second insulating layer;
The first transistor and the first electrode are electrically connected;
The display panel, wherein the second transistor and the fourth electrode are electrically connected. In claim 4,
Having a colored layer and a light shielding layer,
The first portion of the first display element has a portion overlapping the colored layer,
The second transistor has a portion overlapping the light shielding layer,
The colored layer is located between the second substrate and the fourth electrode;
The colored panel and the light shielding layer are display panels having portions provided on the same plane. In any one of Claims 2 thru | or 5,
The liquid crystal-containing layer includes a polymer dispersed liquid crystal or a polymer network type liquid crystal. A display panel according to any one of claims 1 to 6;
And a display module. A display panel according to any one of claims 1 to 6, or a display module according to claim 7,
An electronic device including an antenna, a battery, a housing, a speaker, a microphone, an operation switch, or an operation button.