CN114335370B - Light emitting device, display substrate and display panel - Google Patents
Light emitting device, display substrate and display panel Download PDFInfo
- Publication number
- CN114335370B CN114335370B CN202111633374.3A CN202111633374A CN114335370B CN 114335370 B CN114335370 B CN 114335370B CN 202111633374 A CN202111633374 A CN 202111633374A CN 114335370 B CN114335370 B CN 114335370B
- Authority
- CN
- China
- Prior art keywords
- electrode
- light emitting
- layer
- blocking layer
- sub
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Electroluminescent Light Sources (AREA)
- Devices For Indicating Variable Information By Combining Individual Elements (AREA)
Abstract
The present disclosure provides a light emitting device, a display substrate, and a display panel, the light emitting device including a first electrode structure, a second electrode structure, and a light emitting functional layer between the first electrode structure and the second electrode structure. The first electrode structure includes a first electrode and a charge blocking layer for blocking holes, which are stacked on each other. When the voltage from the external circuit is small, holes are difficult to enter the light-emitting functional layer beyond the potential barrier formed by the charge blocking layer, so that the light-emitting functional layer cannot be excited to emit light; under the condition of larger voltage from an external circuit, the charge blocking layer can not block holes, and can not influence the brightness of the light emitting device in a light emitting state.
Description
Technical Field
The present disclosure relates to the field of display, and in particular, to a light emitting device, a display substrate, and a display panel.
Background
An Organic Light-Emitting Diode (OLED) display device is an Organic thin film electroluminescent device, and has been greatly paid attention to because of its advantages of simple manufacturing process, low cost, low power consumption, high brightness, wide viewing angle, high contrast ratio, and realization of flexible display.
In the display stage, the luminous intensity of the display device is adjusted to realize image display, and the contrast of the image directly influences the user experience. However, the current display device is limited to the limitation of the structure thereof, and in the case of low gray scale display (low brightness or off state) is required, the display device can still emit light due to the leakage current existing in the driving circuit, so that the display device cannot realize real low gray scale light emission or does not emit light at all, and the contrast ratio of the display image of the display product is limited, and the user requirement is difficult to meet.
Disclosure of Invention
The disclosure provides a light emitting device, a display substrate and a display panel, wherein a charge blocking layer is arranged on a first electrode of the light emitting device to block holes to a certain extent, so that difficulty of hole transition is increased, the light emitting device is prevented from emitting light under low gray-scale current or voltage, and contrast ratio of display images of the display substrate and the display panel is improved.
A first aspect of the present disclosure provides a light emitting device including a first electrode structure, a second electrode structure, and a light emitting functional layer between the first electrode structure and the second electrode structure. The first electrode structure includes a first electrode and a charge blocking layer for blocking holes.
In the above scheme, under the condition that the voltage from an external circuit is small, holes are difficult to enter the light-emitting functional layer beyond the potential barrier formed by the charge blocking layer, so that the light-emitting functional layer cannot be excited to emit light; under the condition of larger voltage from an external circuit, the charge blocking layer can not block holes, and can not influence the brightness of the light emitting device in a light emitting state.
In one embodiment of the first aspect of the present disclosure, the charge blocking layer is an insulating layer and the thickness of the charge blocking layer is so small that it breaks down at non-lowest gray scale driving voltages, i.e. the thickness of the charge blocking layer is configured such that the charge blocking layer breaks down at non-lowest gray scale driving voltages and is insulating at lowest gray scale voltages. For example, the material of the charge blocking layer has a forbidden bandwidth of not less than 4.5eV.
In the scheme, the voltage required by the charge blocking layer when the charge blocking layer allows the carriers to pass can be adjusted by designing the forbidden bandwidth of the charge blocking layer, so that the minimum driving voltage of the light emitting device capable of emitting light is adjusted, and the light emitting device is ensured not to emit light at the lowest gray level (for example, zero gray level).
In a specific embodiment of the first aspect of the present disclosure, the charge blocking layer has a thickness of 1 to 30 nanometers.
In a specific embodiment of the first aspect of the present disclosure, the material of the charge blocking layer comprises at least one of silicon oxide, silicon nitride, aluminum oxide, hafnium oxide, zirconium oxide, and magnesium oxide.
In a specific embodiment of the first aspect of the present disclosure, the first electrode is located between the charge blocking layer and the light emitting functional layer.
In the scheme, the influence of the arrangement of the charge blocking layer on the first electrode, the second electrode structure and the film layer design of the light-emitting functional layer of the light-emitting device can be reduced.
In another embodiment of the first aspect of the present disclosure, the charge blocking layer is located between the first electrode and the light emitting functional layer.
In the above solution, the charge blocking layer is located between the first electrode and the light emitting functional layer, and in a practical process, it is equivalent to preparing the charge blocking layer above the first electrode, so that holes must pass through the charge blocking layer before entering the light emitting functional layer.
In another embodiment of the first aspect of the present disclosure, the first electrode includes a stacked first sub-electrode, a second sub-electrode, and a third sub-electrode, the second sub-electrode and the third sub-electrode are sequentially arranged in a direction from the first sub-electrode to the light emitting functional layer, the first sub-electrode is a light reflecting electrode, the charge blocking layer is located between the first sub-electrode and the third sub-electrode, and a sum of optical thicknesses of the second sub-electrode and the charge blocking layer is an integer multiple of 1/2 of a center wavelength of outgoing light of the light emitting functional layer. For example, further, the charge blocking layer is configured to be located between the second sub-electrode and the third sub-electrode.
In the above scheme, the light rays meeting the conditions can generate interference constructive so as to be reemitted from the first electrode structure, and the wavelength range of the emergent light rays is more toward the center wavelength, so that the color purity is higher; in addition, undesirable light may be consumed (e.g., interference cancellation, etc.) in the first electrode structure, thereby reducing the proportion of interfering light emitted in the light emitting device and further improving the color purity of the emitted light. In addition, the thickness of the first electrode structure is not increased by the arrangement of the charge blocking layer, so that adverse effects on the design size of the light-emitting device are avoided.
In a specific embodiment of the first aspect of the present disclosure, the light emitting functional layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer, which are sequentially arranged from the first electrode structure to the second electrode structure, and further includes an electron blocking layer between the light emitting layer and the first electrode structure and a hole blocking layer between the light emitting layer and the second electrode structure.
A second aspect of the present disclosure provides a display substrate including an array substrate and a display function layer. The array substrate comprises a substrate and a driving circuit layer positioned on the substrate. The display function layer includes a plurality of light emitting devices as in the first aspect described above. The driving circuit layer comprises a plurality of pixel driving circuits connected with the light emitting devices in a one-to-one correspondence manner, each pixel driving circuit comprises a driving transistor, and the first electrode structure of the light emitting device is electrically connected with the source electrode or the drain electrode of the driving transistor of the corresponding pixel driving circuit.
In a specific embodiment of the second aspect of the present disclosure, the first electrode structure of the light emitting device and the source electrode or the drain electrode of the corresponding driving transistor are directly connected.
In another embodiment of the second aspect of the present disclosure, the pixel driving circuit includes a plurality of switching transistors, and the first electrode structure of the light emitting device and the source electrode or the drain electrode of the corresponding driving transistor are electrically connected through at least one switching transistor.
A third aspect of the present disclosure provides a display panel including the display substrate in the second aspect described above.
Drawings
Fig. 1 is a schematic plan view of a display substrate according to an embodiment of the disclosure.
Fig. 2 is a cross-sectional view of the display substrate shown in fig. 1.
Fig. 3 is a schematic structural diagram of a pixel region in the display substrate shown in fig. 1.
Fig. 4 is a schematic view of a portion of a light emitting device of the display substrate shown in fig. 3, and illustrates a connection manner of the light emitting device and a transistor.
Fig. 5 is a schematic view of a portion of another light emitting device of the display substrate shown in fig. 3, and illustrates a connection manner of the light emitting device and a transistor.
Fig. 6 is a schematic view of a portion of another light emitting device of the display substrate shown in fig. 3, and illustrates a connection manner of the light emitting device and a transistor.
Fig. 7 is a schematic view of a portion of another light emitting device of the display substrate shown in fig. 3, and illustrates a connection manner of the light emitting device and a transistor.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
An Organic Light-Emitting Diode (OLED) is a device driven by a current, and in the display field, the current input to the OLED is generally controlled by a thin film transistor (Thin Film Transistor, abbreviated as "TFT") in a driving circuit, which may be a driving transistor, so that the magnitude of the current output from the TFT may be controlled by controlling the gate voltage of the TFT (different gate voltages correspond to the on/off state and the on degree of the TFT), thereby controlling the Light Emitting state (e.g., on or off) and the Light Emitting brightness of the OLED.
The OLED includes a light emitting layer in which electrons and holes are recombined to excite light when the OLED is energized with current. In practical applications, at least for the purpose of reducing power consumption, the current used for driving the OLED is reduced, and for the purpose of ensuring the brightness of the OLED, the material of the light-emitting layer is developed to be more favorable for electron and hole recombination, which results in that the light-emitting layer can emit light under low current driving, that is, the OLED cannot achieve a real shutdown, that is, the OLED can still emit light under a so-called black state (corresponding shutdown), so that the contrast ratio of the displayed image is low.
At least one embodiment of the present disclosure provides a light emitting device, a display substrate, and a display panel, which can solve the above technical problems. The light emitting device includes a first electrode structure, a second electrode structure, and a light emitting functional layer between the first electrode structure and the second electrode structure. The first electrode structure includes a first electrode and a charge blocking layer for blocking holes, so that carriers (e.g., holes) injected from the side of the first electrode structure where the light emitting functional layer is located need to pass through the charge blocking layer before entering the light emitting functional layer. In this way, the first electrode and the charge blocking layer are stacked, and a current (hole) from an external circuit (for example, a pixel driving circuit described below) passes through the blocking of the charge blocking layer before passing through the first electrode to enter the light emitting function layer, and in the case that the voltage from the external circuit is small, the hole is difficult to cross the barrier to enter the light emitting function layer due to the barrier formed by the wide forbidden band width of the charge blocking layer, so that the light emitting function layer is not excited to emit light; in the case where the voltage from the external circuit is large, the charge blocking layer blocks charges (holes) to change the built-in electric field between the first electrode and the charge blocking layer and cause bending of the energy band, which results in lowering of the potential barrier so that the charge blocking layer does not act as a barrier to the holes, and thus, the arrangement of the charge blocking layer does not affect the luminance of the light emitting device in the light emitting state.
It should be noted that, in the embodiment of the present disclosure, the first electrode may be an anode of the light emitting device, and the second electrode may be a cathode of the light emitting device.
Next, a structure of a light emitting device, a display substrate, and a display panel according to at least one embodiment of the present disclosure will be described with reference to the accompanying drawings. In addition, in the embodiments, the structure of the light emitting device in the display substrate is described in detail by describing the display substrate. In addition, in the drawings, a space rectangular coordinate system is established with reference to the plane of the display substrate (the direction from the first electrode structure to the second electrode structure of the light emitting device is perpendicular to the plane), so as to describe the positions of the respective elements in the light emitting device, the display substrate and the display panel, and in the space rectangular coordinate system, the X axis and the Y axis are parallel to the plane of the display substrate, and the Z axis is perpendicular to the plane of the display substrate.
In one embodiment of the present disclosure, as shown in fig. 1 to 4, the display substrate 10 includes an array substrate 100 and a display function layer 200 stacked together. The array substrate 100 includes a base 110 and a driving circuit layer 120. The driving circuit layer 120 and the display function layer 200 are sequentially stacked on the substrate 110. The display substrate 10 is divided into a display area 11 and a non-display area 12 located around the display area 11, and at least a partial area of the non-display area 12 may be used to constitute a bezel area in the final product (e.g., display panel). The display function layer 200 is located in the display area 11 and includes a plurality of light emitting devices 201. The driving circuit layer 120 includes a plurality of pixel driving circuits connected to the light emitting devices 201 in one-to-one correspondence, each pixel driving circuit including a driving transistor TFT, and the first electrode structure 210 of the light emitting device 201 is electrically connected to a source electrode or a drain electrode of the driving transistor TFT of the corresponding pixel driving circuit.
For example, the pixel driving circuit includes a plurality of transistors, capacitors, and the like, for example, formed in various forms such as 2T1C (i.e., 2 thin film transistors (T) and 1 capacitor (C)), 3T1C, or 7T1C, wherein at least one thin film transistor is a driving transistor, and the other thin film transistors may be switching transistors.
For example, in the display substrate provided in some embodiments of the present disclosure, the first electrode structure of the light emitting device and the source electrode or the drain electrode of the corresponding driving transistor are directly connected.
For example, in the display substrate provided in other embodiments of the present disclosure, the pixel driving circuit includes a plurality of switching transistors, the first electrode structure of the light emitting device and the source electrode or the drain electrode of the corresponding driving transistor are electrically connected through at least one switching transistor, and the switching transistor for connecting the first electrode structure and the driving transistor may be configured to be independently controlled to further control the switching of the light emitting device, thereby cooperating with the pixel driving circuit to improve the reliability of the state control of the light emitting device.
In at least one embodiment of the present disclosure, the light emitting functional layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer arranged from the first electrode structure to the second electrode structure. For example, the light emitting functional layer may further include an electron blocking layer between the light emitting layer and the first electrode structure and a hole blocking layer between the light emitting layer and the second electrode structure.
In the embodiment shown in fig. 3 and 4, the light emitting device 201 includes a first electrode structure 210, a light emitting function layer 220, and a second electrode structure 230 sequentially stacked on the driving circuit layer 120, the first electrode structure 210 including a first electrode 211 and a charge blocking layer 212 for blocking holes. The charge blocking layer generally has a wider forbidden bandwidth, when current is injected into the first electrode structure of the light emitting device through the TFT of the pixel driving circuit during driving of the light emitting device, when the current is smaller, the charge (here, holes) cannot easily cross the potential barrier formed by the charge blocking layer and reach the light emitting functional layer of the light emitting device, namely, the current of the light emitting device under low voltage is obviously reduced, so that the light emitting device is difficult to be conducted, the brightness of excitation light is further reduced or the excitation light is not generated, and the light emitting brightness of the light emitting device under dark state is further reduced or the light emitting device does not emit light at all; in addition, if the current entering the first electrode structure increases further, charges (here holes) start to accumulate on the side of the charge blocking layer facing away from the light emitting function layer, which changes the built-in electric field on the side of the charge blocking layer facing away from the light emitting function layer and causes bending of the energy band, so that the potential barrier formed by the charge blocking layer is reduced, allowing a large amount of charges to pass through the charge blocking layer, i.e. at high currents, the charge blocking layer itself does not play a role in blocking the charge entry, and in the case of very thin thickness (e.g. 1 to 30 nm) of the charge blocking layer, hardly acts on the internal resistance of the light emitting device, so that charge injection at high current density and device voltage are not affected. Thus, for a screen (display substrate or display panel), under the condition of low gray scale of the screen, the existence of the charge blocking layer causes that under the condition that low current is provided for the light emitting device, charges can accumulate in the charge blocking layer and cannot enter the light emitting layer of the light emitting device to be compounded, so that the light emitting device is not bright, and after the current provided by the TFT is further increased, the charges start to enter the light emitting layer beyond the charge blocking layer, the light emitting device starts to emit light, and under the condition, the charge blocking layer loses the effect of blocking the charges, so that the arrangement of the charge blocking layer cannot influence the display brightness of the screen under low brightness.
It should be noted that both the electron blocking layer and the hole blocking layer have a function of blocking low charges, but the electron blocking layer serves to block electrons so that holes pass therethrough, and the hole blocking layer serves to block holes so that electrons and holes are blocked from diffusing out of the light emitting layer, thereby improving the light emitting efficiency and lifetime of the entire light emitting device. The charge blocking layer is used for blocking charge (comprising electrons and holes) injection, so that the difficulty of charge injection is improved, and the starting voltage of the light-emitting device is improved, namely, the charge blocking layer, the electron blocking layer and the hole blocking layer are formed by different materials, and correspondingly, the charge blocking layer, the electron blocking layer and the hole blocking layer are also of completely different structures.
In a light emitting device provided by at least one embodiment of the present disclosure, the charge blocking layer is an insulating layer, and the thickness of the charge blocking layer is so small as to be broken down at a non-lowest gray scale driving voltage, i.e., the thickness of the charge blocking layer is set such that the charge blocking layer is broken down at the non-lowest gray scale driving voltage and is insulated at the lowest gray scale voltage. Therefore, by designing the forbidden bandwidth of the charge blocking layer, the voltage required by the charge blocking layer when the charge blocking layer allows the carriers to pass can be adjusted, so that the minimum driving voltage of the light emitting device capable of emitting light is adjusted, and the light emitting device is ensured not to emit light at the lowest gray level (for example, zero gray level). For example, the material of the charge blocking layer has a forbidden bandwidth of not less than 4.5eV, so that in the current driving mode of the display substrate, the light emitting device does not emit light under a driving voltage (for example, a voltage formed by a leakage current of the driving transistor) in a dark state (for example, zero gray level), thereby improving the contrast ratio of a display image.
In the light emitting device provided in at least one embodiment of the present disclosure, the thickness of the charge blocking layer (e.g., the dimension along the Z-axis direction in fig. 4) is 1 to 30 nanometers, for example, further 2 nanometers, 5 nanometers, 10 nanometers, 15 nanometers, 20 nanometers, 25 nanometers, or the like. In the above thickness range, the charge blocking layer can remarkably reduce or avoid light emission of the light emitting device in a black state, and ensure that the light emitting device is easily broken down when light emission is required without affecting the light emitting brightness of the light emitting device in a bright state.
In a light emitting device provided in at least one embodiment of the present disclosure, a material of the charge blocking layer includes at least one of silicon oxide, silicon nitride, aluminum oxide, hafnium oxide, zirconium oxide, magnesium oxide, and the like.
In the embodiment of the present disclosure, the stacking order of the first electrode and the charge blocking layer in the first electrode structure is not limited on the premise that the charge (hole) in the first electrode structure can be ensured to enter the light emitting functional layer by the charge blocking layer. For example, in some embodiments of the present disclosure, a charge blocking layer is located between the first electrode and the light emitting functional layer; alternatively, in other embodiments of the present disclosure, the first electrode is located between the charge blocking layer and the light emitting functional layer; alternatively, in other embodiments of the present disclosure, the first electrode is a multi-layered structure, and the charge blocking layer is located between adjacent structural layers of the first electrode so as to be located inside the first electrode, e.g., the first electrode includes at least two sub-electrodes stacked with the charge blocking layer located between adjacent sub-electrodes. Next, the structure of the light emitting device in these three cases will be described by different embodiments.
In the light emitting device provided in some embodiments of the present disclosure, the charge blocking layer is located between the first electrode and the light emitting functional layer, as shown in fig. 4 and fig. 5, the above scheme is equivalent to that of preparing the charge blocking layer 212, 212a on the first electrode 211, 211a, so as to avoid damage to the charge blocking layer 212, 212a caused by the preparation process (such as magnetron sputtering, lithography, etc.) of the first electrode 211, 211 a; in addition, in a practical process, when the first electrodes 211 and 211a are connected to an external circuit, it is necessary to provide a via hole to expose an output terminal of the external circuit (for example, a source electrode or a drain electrode of a transistor therein), and in order to make the light emitting function layer 220 have a high flatness, a portion of the first electrodes 211 and 211a located in the via hole may avoid a pixel opening (for example, an opening of a pixel defining layer described below), so that even if the charge blocking layers 212 and 212a break at the via hole, the charge blocking layers 212 and 212a may space the first electrodes 211 and 211a and the light emitting function layer 220 at the pixel opening position, so that a hole may enter the light emitting function layer 220 only after passing through the charge blocking layers 212 and 212 a.
The display function layer may include a pixel defining layer, and in the case where the charge blocking layer is located between the first electrode and the light emitting function layer, the charge blocking layer may be formed before or after the pixel defining layer according to the needs of an actual process. For example, as shown in fig. 3, the display function layer 200 may further include a pixel defining layer 202 on the array substrate 100. The pixel defining layer 202 defines a plurality of openings therein for defining light emitting devices (at least for accommodating light emitting functional layers in the light emitting devices). Thus, if the charge blocking layer is formed first, and then the pixel defining layer is formed on the charge blocking layer, as shown in fig. 4, the charge blocking layer 212 can have a higher flatness, so as to ensure the continuity of the charge blocking layer 212; alternatively, if the pixel defining layer having the opening is formed first, and then the charge blocking layer is deposited to cover the pixel defining layer, as shown in fig. 5, it is possible to avoid damaging the charge blocking layer during the formation of the opening in the pixel defining layer, and to avoid direct contact between the first electrode and the light emitting functional layer.
In other embodiments of the present disclosure, a light emitting device is provided in which a first electrode is located between a charge blocking layer and a light emitting functional layer. In this way, the influence of the arrangement of the charge blocking layer on the first electrode, the second electrode structure and the film design of the light-emitting function layer of the light-emitting device can be reduced, namely, the light-emitting device can still use the current light-emitting function layer, and the energy bands and the like of all the film layers of the light-emitting function layer do not need to be redesigned, so that the design cost and the production process cost of the whole light-emitting device are reduced; in addition, the charge blocking layer is formed in front of the first electrode, so that the via hole for communicating the first electrode and the external circuit can be covered, even if the charge blocking layer breaks at the via hole, carriers output by the external circuit need to pass through the part of the charge blocking layer located in the via hole and then enter the first electrode, and therefore the risk that carriers (holes) cannot pass through the charge blocking layer and directly enter the light-emitting functional layer due to the fact that the charge blocking layer breaks at the via hole can be reduced. For example, as shown in fig. 6, in a practical process, the charge blocking layer 212b may cover a via hole for connecting the first electrode 211b and an external circuit, for example, the charge blocking layer 212b covers a drain surface of the thin film transistor exposed by the via hole, so as to ensure that the external circuit (for example, a drain electrode of the thin film transistor included therein) and the first electrode 211b are still separated by the charge blocking layer 212b, and thus, holes from the external circuit must pass through the charge blocking layer 212b before entering the light emitting function layer 220, thereby solving the above technical problem.
In the light emitting device provided in other embodiments of the present disclosure, the first electrode has a multi-layer structure, and the charge blocking layer is located inside the first electrode, that is, between two adjacent layers of the first electrode, specifically, the structure shown in fig. 7 may be referred to. For example, the first electrode is formed by stacking three sub-electrodes, which are a first sub-electrode 2111c, a second sub-electrode 2112c, and a third sub-electrode 2113c stacked in this order, and the first sub-electrode 2111c, the second sub-electrode 2112c, and the third sub-electrode 2113c are arranged in this order in the direction from the first sub-electrode 2111c to the light emitting functional layer 220. The charge blocking layer 212c is located between the second sub-electrode 2112c and the third sub-electrode 2113 c.
In the case where the first electrode has a multilayer structure, the first electrode is not limited to include three sub-electrodes as shown in fig. 7, and the number of sub-electrodes included may be two, four, or more than four.
For example, in some embodiments of the present disclosure, in the case where the first electrode includes a first sub-electrode, a second sub-electrode, and a third sub-electrode as shown in fig. 7, the first sub-electrode and the third sub-electrode may be formed of a high work function oxide electrode material such as indium tin oxide, etc., the second sub-electrode may be formed of a metal material such as aluminum, silver, copper, titanium, etc., to ensure that the first electrode has a relatively small sheet resistance, and may also be made to have a light reflecting effect to improve the light emitting efficiency of the light emitting device.
For example, in other embodiments of the present disclosure, in the case where the first electrode is a multilayer structure, the first electrode may be further provided in a structure similar to an optical resonator to improve the light emitting luminance and color purity (the higher the color purity, the less parasitic light) of the light emitting device. Illustratively, as shown in FIG. 7, the first sub-electrode 2111c is a light reflective electrode and the charge blocking layer 212c is positioned between the first sub-electrode 2111c and the third sub-electrode 2113 c. The sum of the optical thicknesses of the second sub-electrode 2112c and the charge blocking layer 212c is an integral multiple of 1/2 of the center wavelength of the emitted light in the light emitting functional layer 220. For example, further, the charge blocking layer 212c is configured to be located between the second sub-electrode 2112c and the third sub-electrode 2113 c. In this way, in the case where light (light emitted by the light-emitting functional layer and/or light emitted by the light-emitting functional layer) is incident into the first electrode structure, light satisfying the above conditions may exhibit interference constructive in the structure formed by the second sub-electrode 2112c and the charge blocking layer 212c and be emitted again from the first electrode structure, and the wavelength range of the emitted light may be more toward the center wavelength, thereby having higher color purity; in addition, light rays which do not meet the above requirements are consumed (e.g., interference cancellation, etc.) in the first electrode structure, thereby reducing the proportion of the disturbing light rays emitted in the light emitting device and further improving the color purity of the emitted light rays. In addition, in the scheme, the thickness of the first electrode structure is not additionally increased by the arrangement of the charge blocking layer (the design thickness of the second sub-electrode is correspondingly reduced along with the arrangement of the charge blocking layer), so that the design size of the light emitting device is not adversely affected.
For example, the first sub-electrode may employ a metal material having a high light-reflecting property, such as a metal of chromium, silver, lithium, magnesium, calcium, strontium, aluminum, indium, copper, gold, or the like, or an alloy thereof; for example, the second and third sub-electrodes may be transparent electrodes such as Indium Tin Oxide (ITO), indium Zinc Oxide (IZO), indium Gallium Oxide (IGO), gallium Zinc Oxide (GZO), indium Gallium Zinc Oxide (IGZO), zinc oxide (ZnO), indium oxide (In 2O 3), aluminum Zinc Oxide (AZO), carbon nanotubes, and the like, wherein the third sub-electrode may further select a material having a high work function, for example, may include one or a combination of ITO, IZO, GZO and IGZO, and the like.
It should be noted that, in the embodiment of the present disclosure, each light emitting device corresponds to one sub-pixel of the display substrate (or display panel), the sub-pixels are classified into a plurality of types to emit light of different colors, and the colors of the light emitted from the different types of sub-pixels are different, so that in the case where the first electrode is provided in a structure like an optical resonator, the optical thickness of the structure formed by the second sub-electrode and the charge blocking layer is different in the light emitting devices of different colors of emitted light. For example, the sub-pixels of the display substrate may be classified into three types of sub-pixels of R (red), G (green), and B (blue), and the optical thickness of the structure formed by the second sub-electrode and the charge blocking layer in the R sub-pixel is different from the optical thickness of the structure formed by the second sub-electrode and the charge blocking layer in the G sub-pixel.
At least one embodiment of the present disclosure provides a display panel including the display substrate of any one of the embodiments described above.
For example, in the display panel provided in some embodiments of the present disclosure, a display functional layer of a display substrate may be covered with an encapsulation layer to encapsulate the display substrate, or a cover plate may be provided to encapsulate the display substrate with a box. For example, further, a touch structure, an optical film (such as a polarizer, a condensing sheet, or a color film) and the like may be further disposed on the display substrate after the packaging is completed, and the related design of the current display panel may be referred to, which is not described herein.
For example, the device to which the display panel in the embodiments of the present disclosure is applied may be any product or component having a display function, such as a television, a digital camera, a mobile phone, a wristwatch, a tablet computer, a notebook computer, a navigator, and the like.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is to be construed as including any modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (11)
1. A light emitting device comprising a first electrode structure, a second electrode structure, and a light emitting functional layer between the first electrode structure and the second electrode structure, wherein,
the first electrode structure includes a first electrode and a charge blocking layer for blocking holes, the charge blocking layer being an insulating layer, and the thickness of the charge blocking layer being configured to have a thickness that breaks down at a non-lowest gray driving voltage and is insulating at a lowest gray voltage, and
the first electrode is an anode and comprises at least two sub-electrodes stacked, and the charge blocking layer is positioned between adjacent sub-electrodes.
2. A light-emitting device according to claim 1, wherein,
the forbidden bandwidth of the material of the charge blocking layer is not less than 4.5eV.
3. A light-emitting device according to claim 2, wherein,
the thickness of the charge blocking layer is 1-30 nanometers.
4. A light-emitting device according to claim 2, wherein,
the material of the charge blocking layer includes at least one of silicon oxide, silicon nitride, aluminum oxide, hafnium oxide, zirconium oxide, and magnesium oxide.
5. The light-emitting device according to any one of claim 1 to 4, wherein,
the first electrode includes at least two sub-electrodes stacked, and the charge blocking layer is located between adjacent sub-electrodes.
6. The light-emitting device according to any one of claim 1 to 4, wherein,
the first electrode comprises a first sub-electrode, a second sub-electrode and a third sub-electrode which are stacked, the second sub-electrode and the third sub-electrode are sequentially arranged along the direction from the first sub-electrode to the luminous functional layer, the first sub-electrode is a light reflection electrode, the charge blocking layer is positioned between the first sub-electrode and the third sub-electrode, and
the sum of the optical thicknesses of the second sub-electrode and the charge blocking layer is an integral multiple of 1/2 of the center wavelength of the outgoing light of the light emitting functional layer.
7. The light emitting device of claim 6, wherein the charge blocking layer is configured to be positioned between the second sub-electrode and the third sub-electrode.
8. The light-emitting device according to any one of claims 1 to 4, wherein the light-emitting functional layer comprises a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer arranged from the first electrode structure to the second electrode structure, and
the light emitting functional layer further includes an electron blocking layer between the light emitting layer and the first electrode structure and a hole blocking layer between the light emitting layer and the second electrode structure.
9. A display substrate, comprising:
the array substrate comprises a substrate and a driving circuit layer positioned on the substrate; and
a display functional layer comprising a plurality of light emitting devices according to any one of claims 1 to 8;
the driving circuit layer comprises a plurality of pixel driving circuits which are connected with the light emitting devices in a one-to-one correspondence mode, each pixel driving circuit comprises a driving transistor, and the first electrode structure of the light emitting device is electrically connected with the source electrode or the drain electrode of the driving transistor of the corresponding pixel driving circuit.
10. The display substrate of claim 9, wherein the display substrate comprises a transparent substrate,
the first electrode structure of the light emitting device is directly connected with the source electrode or the drain electrode of the corresponding driving transistor; or alternatively
The pixel driving circuit includes a plurality of switching transistors, and a first electrode structure of the light emitting device and a source electrode or a drain electrode of the corresponding driving transistor are electrically connected through at least one switching transistor.
11. A display panel comprising the display substrate according to claim 9 or 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111633374.3A CN114335370B (en) | 2021-12-28 | 2021-12-28 | Light emitting device, display substrate and display panel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111633374.3A CN114335370B (en) | 2021-12-28 | 2021-12-28 | Light emitting device, display substrate and display panel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114335370A CN114335370A (en) | 2022-04-12 |
| CN114335370B true CN114335370B (en) | 2023-08-29 |
Family
ID=81014477
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111633374.3A Active CN114335370B (en) | 2021-12-28 | 2021-12-28 | Light emitting device, display substrate and display panel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114335370B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103137882A (en) * | 2011-11-22 | 2013-06-05 | 海洋王照明科技股份有限公司 | Organic electroluminescent device and production method thereof |
| CN104124367A (en) * | 2013-04-24 | 2014-10-29 | 海洋王照明科技股份有限公司 | Organic light-emitting device and preparation method thereof |
| CN106848076A (en) * | 2017-01-06 | 2017-06-13 | 西安交通大学 | A kind of organo-mineral complexing perovskite LED device and preparation method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TW595259B (en) * | 2003-01-28 | 2004-06-21 | Ind Tech Res Inst | Organic electroluminescent device |
-
2021
- 2021-12-28 CN CN202111633374.3A patent/CN114335370B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103137882A (en) * | 2011-11-22 | 2013-06-05 | 海洋王照明科技股份有限公司 | Organic electroluminescent device and production method thereof |
| CN104124367A (en) * | 2013-04-24 | 2014-10-29 | 海洋王照明科技股份有限公司 | Organic light-emitting device and preparation method thereof |
| CN106848076A (en) * | 2017-01-06 | 2017-06-13 | 西安交通大学 | A kind of organo-mineral complexing perovskite LED device and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114335370A (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10879320B2 (en) | Organic light-emitting display panel and display apparatus | |
| US11871634B2 (en) | Display device | |
| CN108231830B (en) | Organic light emitting display device | |
| EP2280435B1 (en) | Organic light emitting diode display device | |
| US7030553B2 (en) | OLED device having microcavity gamut subpixels and a within gamut subpixel | |
| US8400055B2 (en) | Organic electroluminescence apparatus with metal auxiliary wiring | |
| US20160233458A1 (en) | Organic light emitting display panel and display apparatus | |
| US9130190B2 (en) | Display and method of manufacturing the same | |
| JP2015053137A (en) | Organic electroluminescent display device | |
| CN113644220A (en) | Display panel, preparation method of display panel and display device | |
| JP2013089444A (en) | Organic light-emitting device, manufacturing method therefor and electronic apparatus | |
| JP2013207010A (en) | Light-emitting element, manufacturing method therefor, display device and luminaire | |
| US20230165094A1 (en) | Display device, display panel and manufacturing method thereof, driving circuit and driving method | |
| US11622433B2 (en) | Display panel, manufacturing method and drive control method thereof, and display apparatus | |
| US20220320472A1 (en) | Display device | |
| CN114335370B (en) | Light emitting device, display substrate and display panel | |
| US11539034B2 (en) | Display device and electronic apparatus having lenses disposed correspondingly to respective pixel electrodes | |
| KR20140079017A (en) | Organic Light Emitting Display Device and Method for Manufacturing The Same | |
| WO2018207484A1 (en) | Display device and electronic apparatus | |
| CN116568099B (en) | Array substrate, preparation method thereof and display panel | |
| US20240023400A1 (en) | Display panel and display module | |
| CN114242749A (en) | Display device | |
| CN113594212A (en) | Display panel, preparation method thereof and display device | |
| CN117396038A (en) | Display panel and display device thereof | |
| CN116386539A (en) | Display device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |