JP4419691B2 - Organic EL devices, electronic devices - Google Patents

Description

  The present invention relates to an organic EL device and an electronic device.

  2. Description of the Related Art In recent years, an organic EL device including a plurality of organic electroluminescence (hereinafter referred to as organic EL) elements for each pixel as a means for displaying information has been proposed in electronic devices such as notebook computers, mobile phones, and electronic notebooks. In general, an organic EL element has a configuration in which an organic functional layer including an organic EL layer (light emitting layer) is disposed between a pair of opposed electrodes.

As such an organic EL device, for example, Patent Document 1 discloses a configuration in which an optical resonator is provided to reduce the half-value width of the emission spectrum of each pixel.
JP-A-8-213174

  In the organic EL device disclosed in Patent Document 1, an optical resonator structure is configured by a translucent reflective layer and a reflective layer sandwiching an organic EL layer as a light emitting layer, and a spectrum of light emitted from the light emitting layer. It is possible to realize a reduction in the half-value width, improvement in luminous efficiency, generation of coherent light, and the like. Here, in the case where an optical resonator having the same structure is formed for each color pixel, it is often difficult to optimize all colors. This is because when the structure of the optical resonator is optimized with respect to the emission wavelength to be optimized, it is necessary to greatly vary the film thickness of the organic EL layer for each color pixel. In particular, in the organic EL layer of a red (R) pixel, it must be made extremely thick, leading to an increase in driving voltage and a decrease in efficiency.

  The present invention has been made in view of the above problems, and an object of the present invention is to obtain high color purity for all colors in an organic EL device having an optical resonator structure, and the thickness of the organic EL layer. It is an object of the present invention to provide an organic EL device that does not cause problems such as a drive voltage increase based on the fact that the pixel is different for each pixel. Another object of the present invention is to provide an electronic device with excellent reliability.

In order to solve the above problems, an organic EL device of the present invention includes a light reflective electrode, a light transmissive electrode, a light emitting layer formed between the light reflective electrode and the light transmissive electrode, A bank layer having a pixel opening for forming the light emitting layer, and a transflective layer that transmits or reflects light from the light emitting layer only for green and blue pixels of the light transmissive electrode; On the insulating film formed on the substrate , the light emitting layer is disposed between the light reflective electrode and the semi-transmissive reflective layer, the semi-transmissive reflective layer and the semi-transmissive reflective layer The optical distance between the light reflective electrode and the transflective layer is the same as the wavelength of the light emitted from the light emitting layer, so that it acts as an optical resonator with the light reflective electrode. It is disposed at a position that is an integral multiple of the wavelength of light, and the transflective layer is It is formed in a planar shape having an area equal to or larger than the pixel opening at a position overlapping in plan view, and the side surface of the transflective layer and the surface of the transflective layer on the light emitting layer side are used as the light transmissive electrode. A red absorption filter that is covered and absorbs red is disposed between the insulating film and the semi-transmissive reflective layer, and is disposed so as to cover a surface on the light emitting side of the semi-transmissive reflective layer. and said that you are.
In order to solve the above problems, an organic EL device of the present invention is an organic EL device comprising an organic EL layer formed between a light reflective electrode and a light transmissive electrode, and the organic EL device The layer is configured to be capable of emitting a plurality of colors and configured to be capable of emitting one emission color for each pixel unit. The organic EL layer is applied to a predetermined color pixel selected from the pixels. A semi-transmissive reflective layer that selectively transmits or reflects light from the organic EL layer is formed by sandwiching the organic EL layer between the semi-transmissive reflective layer and the light reflective electrode.

  According to such an organic EL device, the transflective layer forms an optical resonator with the light reflective electrode, that is, the light emitted from the organic EL layer to the light reflective electrode side is Reflected by the reflective electrode, and as a result, resonated between the light reflective electrode and the transflective layer. And, as a result of resonance, the reflected light is transmitted through a wavelength that can be transmitted through the transflective layer. On the other hand, a part of the light emitted from the organic EL layer to the transflective layer side is transmitted through the transflective layer and the other part is reflected by the transflective layer. As a result, the light reflective electrode And the transflective layer. And, as a result of resonance, the reflected light is transmitted through a wavelength that can be transmitted through the transflective layer. As described above, the light transmitted through the transflective layer is emitted from the organic EL device and used for display. In the present invention, the reflected light is transmitted through the transflective layer after resonance. Therefore, the color purity of the light emitted from the organic EL device is improved.

  Furthermore, in the present invention, the semi-transmissive reflective layer is selectively formed only for a predetermined color. For example, among organic EL layers to be used, an organic EL layer having a relatively low color purity. A semi-transmissive reflective layer can be selectively formed. In this case, no special configuration is required such as changing the film thickness of the organic EL layer for each color in order to correct the difference in color purity. That is, according to the configuration of the present invention, the film thickness of the organic EL layer can be reduced in common for each pixel. It is possible to prevent or suppress the occurrence of problems such as lowering. In addition, shortening of the life due to thinning of the organic EL layer can be prevented. Of course, the thickness of the hole injection layer need not be changed for each color pixel. As described above, according to the present invention, it is possible to provide an organic EL device having a simple configuration, high color purity, and excellent IVL characteristics.

  In the organic EL device of the present invention, the organic EL layer is composed of a polymer organic EL material and is configured to emit red, green and blue colors, while the transflective layer is composed of green and blue. It can be formed selectively with respect to the pixels. When the polymer organic EL material is applied to the organic EL layer in this manner, the red color purity is relatively high and the green and blue color purity is relatively low. By selectively forming the pixels, it is possible to improve the color purity of each color as a whole. In this case, as described above, the organic EL layer having a specific color (in this case, red) does not need to be particularly thinned or thickened. It is possible to prevent or suppress the occurrence of problems such as an increase in driving speed and a decrease in driving efficiency.

  In the above-described configuration, a red absorption filter that absorbs red may be selectively formed on the light emission side of the transflective layer with respect to the green and blue pixels. In this case, even if a polarizing plate or the like is not provided on the light emission side (display surface side) of the organic EL device, the problem that external light reflected by the transflective layer is emitted from the organic EL device is solved. Will be able to. Therefore, it is possible to provide an organic EL device with high contrast, high color purity, and excellent IVL characteristics.

  The light transmissive electrode may be formed on the inner surface of a predetermined light transmissive substrate, and the red absorption filter may be formed on the inner surface of the light transmissive substrate. With this configuration, there is no shift between the filter and the pixel due to the viewing angle as in the case of forming the filter outside the substrate as in the conventional example, and the effect of the filter can be sufficiently exerted. In addition, by introducing the red absorption filter, it is possible to solve the problem of unevenness on the outer surface of the organic EL device, and it is possible to protect the red absorption filter by the translucent substrate.

  Further, the transflective layer also serves as an electrode, a translucent auxiliary electrode is formed on the light emission side of the transflective layer, and the red absorption filter further absorbs red light on the auxiliary electrode. It can be formed by mixing components. Also in this case, this configuration eliminates the difference between the filter and the pixel due to the viewing angle as in the case of forming the filter outside the substrate as in the conventional example, and the effect of the filter can be sufficiently exerted. In addition, it is possible to eliminate the generation of irregularities due to the introduction of the red absorption filter, and it is possible to protect the red absorption filter by the translucent substrate. Further, since the red absorption filter is not separately formed, it is possible to contribute to downsizing of the organic EL device.

  Next, an electronic apparatus according to the present invention includes the organic EL device according to the present invention as a display unit, for example. According to such an electronic apparatus, it is possible to realize display with high color purity and high contrast.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing to be referred to, the scale may be different for each layer or each member in order to make the size recognizable on the drawing.

(First embodiment)
FIG. 1 is an explanatory view schematically showing a main part of an active matrix type organic EL device 1 in particular, regarding an embodiment of the organic EL device of the present invention. The organic EL device 1 employs an active driving method using thin film transistors.

  The organic EL device 1 includes a circuit element unit 14 including a thin film transistor as a circuit element, a pixel electrode (anode) 111, a functional layer 110 including an organic EL layer (organic EL element), a cathode 12, and a seal on a substrate 2. It has a structure in which stop portions 3 and the like are sequentially stacked.

  As the substrate 2, a glass substrate is used in this example. In addition to the glass substrate, various known substrates used for electro-optical devices and circuit substrates such as a silicon substrate, a quartz substrate, a ceramic substrate, a metal substrate, a plastic substrate, and a plastic film substrate are applied. In the substrate 2, a plurality of pixel areas A as light emitting areas are arranged in a matrix, and when performing color display, for example, corresponding to each color of red (R), green (G), and blue (B). The pixel area A is configured in a predetermined array. In each pixel region A, a pixel electrode 111 is arranged, and in the vicinity thereof, a signal line 132, a power supply line 133, a scanning line 131, scanning lines for other pixel electrodes (not shown), and the like are arranged.

  The sealing portion 3 prevents water and oxygen from entering and prevents the cathode 12 or the functional layer 110 from being oxidized. The sealing portion 3 is applied to the substrate 2 and the sealing is bonded to the substrate 2. Substrate 3b (sealing can) is included. As the material of the sealing resin, for example, a thermosetting resin or an ultraviolet curable resin is used, and in particular, an epoxy resin that is one kind of thermosetting resin is preferably used. The sealing resin is annularly applied to the periphery of the substrate 2 and is applied by, for example, a microdispenser. The sealing substrate 3b is made of glass, metal, or the like, and the substrate 2 and the sealing substrate 3b are bonded to each other via a sealing resin.

FIG. 2 shows a circuit structure of the organic EL device 1.
In FIG. 2, a plurality of scanning lines 131, a plurality of signal lines 132 extending in a direction intersecting the scanning lines 131, and a plurality of power supply lines 133 extending in parallel to the signal lines 132 are wired on the substrate 2. Has been. Further, the pixel region A is formed at each intersection of the scanning line 131 and the signal line 132.
For example, the data line driving circuit 103 including a shift register, a level shifter, a video line, and an analog switch is connected to the signal line 132. The scanning line 131 is connected to a scanning side driving circuit 104 including a shift register and a level shifter.

  In the pixel region A, a first thin film transistor 123 for switching in which a scanning signal is supplied to the gate electrode via the scanning line 131 and a holding for holding an image signal supplied from the signal line 132 via the thin film transistor 123. A capacitor 135, a second driving thin film transistor 124 to which an image signal held by the holding capacitor 135 is supplied to the gate electrode, and the power line 133 when electrically connected to the power line 133 through the thin film transistor 124 Are provided with a pixel electrode 111 (anode) through which a drive current flows, and a functional layer 110 sandwiched between the pixel electrode 111 and the counter electrode 12 (cathode). The functional layer 110 includes an organic EL layer as an organic EL element.

  In the pixel region A, when the scanning line 131 is driven and the first thin film transistor 123 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor 135, and the second potential is changed depending on the state of the holding capacitor 135. The conductive state of the thin film transistor 124 is determined. In addition, a current flows from the power supply line 133 to the pixel electrode 111 through the channel of the second thin film transistor 124, and further a current flows to the counter electrode 12 (cathode) through the functional layer 110. The functional layer 110 emits light according to the amount of current at this time.

FIG. 3 is an enlarged view of the cross-sectional structure of the display region in the organic EL device 1. FIG. 3 shows a cross-sectional structure of three pixel regions corresponding to red (R), green (G), and blue (B) colors. As described above, the organic EL device 1 includes the circuit element unit 14 in which a circuit such as a TFT is formed on the substrate 2, the pixel electrode (anode) 111, the light emitting element unit 11 in which the functional layer 110 is formed, and The cathode 12 is formed by sequentially laminating.
In the organic EL device 1, light emitted from the functional layer 110 to the substrate 2 side passes through the circuit element unit 14 and the substrate 2 and is emitted to the lower side (observer side) of the substrate 2, and the functional layer 110. The light emitted from the opposite side of the substrate 2 is reflected by the cathode 12, passes through the circuit element unit 14 and the substrate 2, and is emitted to the lower side (observer side) of the substrate 2.

  In the circuit element portion 14, a light shielding layer BM made of a light shielding material is formed in an island shape on the substrate 2, and further, a base protective film 2c made of a silicon oxide film is formed so as to cover the island. On the base protective film 2c, an island-shaped semiconductor film 141 made of polycrystalline silicon is formed at a position overlapping the light shielding layer BM in a planar manner. Note that a source region 141a and a drain region 141b are formed in the semiconductor film 141 by high concentration P ion implantation. A portion where P is not introduced is a channel region 141c.

Further, a transparent gate insulating film 142 that covers the base protective film 2c and the semiconductor film 141 is formed in the circuit element portion 14, and the gate insulating film 142 is made of Al, Mo, Ta, Ti, W, or the like. A gate electrode (scanning line) 143 is formed. A transparent first interlayer insulating film 144a and a second interlayer insulating film 144b are formed on the gate electrode 143 and the gate insulating film 142. As each interlayer insulating film, a transparent insulating film made of, for example, SiO ₂ or SiN and having an appropriate thickness (for example, about 300 nm) can be employed.
The gate electrode 143 is provided at a position corresponding to the channel region 141c of the semiconductor film 141. In addition, contact holes 145 and 146 are formed through the first and second interlayer insulating films 144a and 144b and connected to the source and drain regions 141a and 141b of the semiconductor film 141, respectively.

  A transparent pixel electrode 111 made of ITO or the like is formed in an island shape on the second interlayer insulating film 144b, and the contact hole 145 described above is connected to the pixel electrode 111. The other contact hole 146 is connected to the power supply line 133. In this way, the driving thin film transistor 123 including the semiconductor film 141 connected to the pixel electrode 111 is formed in the circuit element portion 14. The circuit element unit 14 is also formed with the storage capacitor 135 and the switching thin film transistor 124 described above, but these are not shown in FIG.

  As described above, the pixel electrode 111, the functional layer 110, and the like are stacked on the second interlayer insulating film 144b. In this embodiment, red (R), green (G), and blue Each pixel of (B) has a different stacked structure. Specifically, in the green (G) and blue (B) pixels, a red absorption filter 125 and a transflective film 126 are formed between the second interlayer insulating film 144b and the pixel electrode 111, respectively. A functional layer 110 is formed above the red absorption filter 125 and the semi-transmissive reflective film 126. On the other hand, in the red (R) pixel, these red absorption filter and transflective film are not formed.

  More specifically, in the red (R) pixel, the pixel electrode 111 is formed by patterning on the second interlayer insulating film 144b, and the light emitting element portion 11 is formed thereon. The light emitting element portion 11 is mainly configured by a functional layer 110 stacked on the pixel electrode 111 and a bank portion 112 that is disposed between the functional layers 110 and partitions each functional layer 110. A cathode 12 made of a reflective metal film such as aluminum is disposed on the functional layer 110.

  On the other hand, in the green (G) pixel, the red absorption filter 125 that absorbs red is arranged on the second interlayer insulating film 144b so as to overlap with the pixel opening or in a slightly larger planar shape than the pixel opening. A semi-transmissive reflective layer 126 that reflects part of the emitted light and transmits part of the emitted light is formed on the red absorption filter 125 so as to overlap with the pixel opening or in a slightly larger planar shape than the pixel opening. Has been. The transflective layer 126 is formed by forming a reflective metal film made of aluminum or the like into a thin film of about 10 nm.

  The pixel electrode 111 is formed by patterning so as to cover the red absorption filter 125 and the transflective layer 126, and the light emitting element portion 11 is formed on the pixel electrode 111. The light emitting element portion 11 is mainly configured by a functional layer 110 stacked on the pixel electrode 111 and a bank portion 112 that is disposed between the functional layers 110 and partitions each functional layer 110. A cathode 12 made of a reflective metal film such as aluminum is disposed on the functional layer 110. The optical distance between the semi-transmissive reflective film 126 and the cathode 12 is designed to be the same as or an integral multiple of the light emission (green light emission) wavelength of the pixel. The reflective layer 126 and the cathode 12 constitute an optical resonator for light that is to be extracted from the pixel.

  In the blue (B) pixel, similarly to the green (G) pixel, the red absorption filter 125 that absorbs red color is slightly larger than the pixel opening on the second interlayer insulating film 144b. They are arranged in a planar shape. A semi-transmissive reflective layer 126 that reflects part of the emitted light and transmits part of the emitted light is formed on the red absorption filter 125 so as to overlap with the pixel opening or in a slightly larger planar shape than the pixel opening. Has been. The transflective layer 126 is formed by forming a reflective metal film made of aluminum or the like into a thin film of about 10 nm.

  The pixel electrode 111 is formed by patterning so as to cover the red absorption filter 125 and the transflective layer 126, and the light emitting element portion 11 is formed on the pixel electrode 111. The light emitting element portion 11 is mainly configured by a functional layer 110 stacked on the pixel electrode 111 and a bank portion 112 that is disposed between the functional layers 110 and partitions each functional layer 110. A cathode 12 made of a reflective metal film such as aluminum is disposed on the functional layer 110. Note that the optical distance between the transflective film 126 and the cathode 12 is designed to be the same as or an integral multiple of the light emission (blue light emission) wavelength of the pixel. The reflective layer 126 and the cathode 12 constitute an optical resonator for light that is to be extracted from the pixel.

In common with the pixels of each color (R, G, B), the pixel electrode 111 is formed by patterning into a substantially rectangular shape in plan view. The thickness of the pixel electrode 111 is preferably in the range of 50 nm to 200 nm (for example, 70 nm), and particularly preferably about 150 nm. As shown in FIG. 3, the bank unit 112 includes an inorganic bank layer (first bank layer) 112 a positioned on the substrate 2 side and an organic bank layer (second bank layer) 112 b positioned away from the substrate 2. Has been configured. The inorganic bank layer 112a is made of an inorganic material such as SiO ₂ or TiO ₂ , for example. The organic bank layer 112b is formed of a resist having heat resistance and solvent resistance such as acrylic resin and polyimide resin.

The functional layer 110 includes a hole injection / transport layer 110a stacked on the pixel electrode 111 and an organic EL layer (light emitting layer) 110b formed adjacent to the hole injection / transport layer 110a. Has been.
The hole injection / transport layer 110a has a function of injecting holes into the organic EL layer 110b and a function of transporting holes inside the hole injection / transport layer 110a. By providing such a hole injection / transport layer 110a between the pixel electrode 111 and the organic EL layer 110b, device characteristics such as light emission efficiency and lifetime of the organic EL layer 110b are improved. Further, in the organic EL layer 110b, holes injected from the hole injection / transport layer 110a and electrons injected from the cathode 12 are recombined in the organic EL layer, and light emission is obtained.
The hole injecting / transporting layer 110a is formed by depositing a mixture (PEDOT / PSS) of a polythiophene derivative such as polyethylenedioxythiophene (PEDOT) and polystyrene sulfonic acid (PSS) by an inkjet method, and is blue ( The B pixel is adjusted to a thickness of 40 nm, and the red (R) and green (G) pixels are adjusted to a thickness of 70 nm. The film thickness of the hole injection / transport layer 110a may be different for each color pixel, but can be the same for all pixels by adjusting the film thickness of the EL layer 110b formed thereon. This simplifies the hole injection / transport layer 110a formation process. For example, the thickness of the hole injection / transport layer 110a can be unified at 50 nm. At that time, the thickness of the organic EL layer 110b is set to 70 nm for the organic EL layer 110b3 for the blue pixel and 90 nm for the organic EL layer 110b2 for the green pixel, thereby simultaneously improving the chromaticity of the blue and green pixels. be able to.

The organic EL layer 110b, in the pixel of red (R), are composed of red organic EL layer 110b ₁ made of a polymer material that emits red (R), the pixel of Like green (G), green (G ) to be configured by the green organic EL layer 110b ₂ made of a polymer material that emits light, a further pixel of blue (B), composed of blue organic EL layer 110b ₃ made of a polymer material that emits blue light (B) Has been. Each color pixel is arranged in a predetermined arrangement (for example, a stripe shape). Each organic EL layer 110b ₁ , 110b ₂ , 110b ₃ was formed by forming each light emitting material (polymer material) by an ink jet method, and was formed to a thickness of about 80 nm.

As, as the light emitting material for example can be used one made of an organic EL material such as rhodamine and its derivatives, form a green organic EL layer 110b ₂ emitting material for forming the red organic EL layer 110b _1, for example, quinacridone and What consists of organic electroluminescent materials, such as the derivative | guide_body, can be used. As the light emitting material for forming a blue organic EL layer 110b _3, it can be used, for example distyryl biphenyl and its derivatives, coumarin and its derivatives, those made of an organic EL material such as tetraphenylbutadiene and its derivatives.

On the other hand, after patterning the pixel electrode 111, the bank 112 first forms an inorganic bank layer 112a made of an inorganic material such as SiO ₂ to a thickness of about 50 nm with a pixel opening, and then polyimide or the like. The organic bank layer 112b made of the above organic material is obtained by forming a pixel opening having a thickness of about 2 μm.

  Next, the cathode (counter electrode) 12 is formed on the entire surface of the light emitting element portion 11 and plays a role of flowing a current through the functional layer 110 in a pair with the pixel electrode 111. In the present example, the cathode 12 is configured by laminating a calcium layer 12a and an aluminum layer 12b as being capable of reducing lithium (Li) ions of the metal organic compound 150. The aluminum layer 12b reflects light emitted from the organic EL layer 110b to the substrate 2 side, and an Ag film, a laminated film of Al and Ag, or the like can be employed in addition to the Al film. Moreover, the thickness can be made into the range of 100 nm-1000 nm, for example.

In addition, as a method of selectively disposing the red absorption filter 125 with respect to the green (G) and blue (B) pixels, for example, an inkjet method or a photolithography method can be employed. Specifically, when the ink jet method is used, first, CF ₄ plasma is applied to the entire surface of the second interlayer insulating film 144b, and the green (G) and blue (B) pixels are irradiated with ultraviolet rays to modify the surface. If this is done, a uniform film can be formed.

In the organic EL device 1 configured as described above, the transflective layer 126 forms an optical resonator with the cathode 12, that is, the light emitted from the organic EL layer 110 to the cathode 12 side is Reflected by the cathode 12, and as a result, resonated between the cathode 12 and the transflective layer 126. As a result of the resonance, the reflected light is transmitted through the semi-transmissive reflective layer 126 when the wavelength is transmitted.
On the other hand, part of the light emitted from the organic EL layer 110 to the transflective layer 126 side is transmitted through the transflective layer 126 and the other part is reflected by the transflective layer 126. As a result, Resonance occurs between the cathode 12 and the transflective layer 126. Then, as a result of resonance, when the wavelength reaches the transflective layer 126, the reflected light is transmitted therethrough.

  As described above, the light transmitted through the transflective layer 126 is emitted from the organic EL device 1 and used for display or the like. In the present embodiment, the reflected light is transmitted after the transflective layer after the resonance. 126, the color purity of the light emitted from the organic EL device 1 is improved, and when this is used as a display device, a display with high luminance and high contrast can be obtained. Has been. In the present embodiment, chromaticity (x, y = 0.14, 0.1) in blue, chromaticity (x, y = 0.35, 0.61) in green, and chromaticity (x, y = in red). 0.66, 0.33) and a surface reflectance of 4%. In an organic EL device that does not include the optical resonator structure (that is, the transflective layer 126), the red absorption filter 125, and the light shielding layer BM, blue chromaticity (x, y = 0.15, 0.2), green And chromaticity (x, y = 0.42, 0.55) and surface reflectance of 70%.

Furthermore, in the present embodiment, the semi-transmissive reflective layer 126 is selectively formed for the green (G) and blue (B) pixels, but the organic EL layer 110 is configured using a polymer material. In this case, green and blue have relatively lower color purity than red.
Therefore, in order to correct the difference in color purity by forming a transflective layer for green (G) and blue (B) pixels having relatively low color purity as in this embodiment. A special configuration such as making the film thickness of the organic EL layer 110 different in color is not necessary.
That is, according to the configuration of the present embodiment, the thickness of the organic EL layer 110 can be reduced in common for each pixel. It is possible to prevent or suppress the occurrence of problems such as these.

  By providing a second filter that absorbs light having a wavelength of 600 nm or less on the light extraction side of the red (R) pixel, the contrast can be further improved and the surface reflectance can be reduced to 3%. it can. Such a second filter can be formed on the red (R) pixel by the ink jet method when the red absorption filter is formed on the green (G) and blue (B) pixels by the ink jet method. Further, instead of providing a second filter separately, a material that absorbs light with a wavelength of 600 nm or less, specifically a pigment such as a red dye or a red pigment, may be mixed into the transparent pixel electrode 111. The same effect as described above can be exhibited.

Hereinafter, the manufacturing method of the organic EL device 1 of the first embodiment will be described.
First, after forming the light shielding layer BM on the substrate 2 by a known photolithography technique, the base protective film 2c and the TFT 123 are formed, and the interlayer insulating films 144a and 144b are formed to form a base of the EL device. Then, a resin layer that absorbs red light is formed on the second interlayer insulating film 144b, and this is selectively formed on the green (G) and blue (B) pixels by the photolithography technique, whereby the red absorption filter 125 is formed. obtain. In this filter forming step, either an ink jet method or a photolithography method may be employed. When the ink jet method is used, first, CF ₄ plasma is applied to the entire surface of the second interlayer insulating film 144b, and ultraviolet rays are selectively irradiated onto the green (G) and blue (B) pixels to modify the surface. Thus, a more uniform film can be obtained.

Next, Al is selectively formed as a transflective layer 126 on the red absorption filter for green (G) and blue (B) pixels. At this time, the film thickness was about 10 nm. Subsequently, ITO as a transparent anode is patterned to a thickness of about 70 nm on all the pixels, and SiO _{2 is formed} to a thickness of about 50 nm as the inorganic bank layer 112a serving as the pixel opening film, and polyimide is further formed as the organic bank layer 112b. A pattern is formed to about 2 μm. Then, a liquid composition containing a PEDOT / PSS material is applied as a material for forming a hole injection / transport layer in the formed bank by an ink jet method, and the blue (B) pixel has a red ( In the R and green (G) pixels, a pattern is formed to a thickness of about 70 nm. Further, a polymer light emitting material is patterned on each color pixel by an ink jet method. The film thickness at this time was about 80 nm in all the light emitting layers. Subsequently, the cathode 12 is formed and a sealing process is performed to obtain the organic EL device 1 of the first embodiment.

(Second Embodiment)
Next, a second embodiment of the organic EL device will be described with reference to FIG. Unlike the first embodiment, the second embodiment is characterized in that a pixel electrode 111 having a function of absorbing red is disposed in each pixel of green (G) and blue (B). Other configurations are substantially the same as those of the first embodiment. Therefore, in this embodiment, parts different from the first embodiment will be particularly described.

  The organic EL device 100 of the second embodiment has the same configuration as the organic EL device 1 of the first embodiment with respect to red (R) pixels. On the other hand, for the green (G) and blue (B) pixels, a pixel having both a filter function for absorbing light having a wavelength of 550 nm or more (corresponding to red) and an electrode (anode) function on the second interlayer insulating film 144b. An electrode 127 is provided. Specifically, a Sn phthalocyanine compound is dispersed in a conductive transparent metal material such as ITO. According to such a configuration, the red absorption filter is not formed, so that the layer can be thinned and the manufacturing process is simplified.

As a method for manufacturing such an organic EL device 100, as in the first embodiment, first, after forming the light shielding layer BM on the substrate 2, the base protective film 2c and the TFT 123 are formed, and interlayer insulating films 144a and 144b are formed. To form a substrate of an EL device. Then, after an inorganic material such as SiO ₂ is formed on the entire surface of the second interlayer insulating film 144b, an inorganic bank layer 112a having pixel openings is formed by a known photolithography technique, while the inorganic bank layer 112a is formed. Similarly, an organic bank layer 112b having a pixel opening is formed.

  Next, a liquid composition in which ITO and Sn phthalocyanine compound are dispersed in a solvent is applied in a bank of each of the green (G) and blue (B) pixels by a dispenser, and the bank in the red (R) pixel. Inside, a liquid composition in which ITO is dispersed in a solvent is applied. Next, after baking this coating film, the silver plating solution is applied to the green (G) and blue (B) pixels by the ink jet method or the dispense method, and transmitted to the green (G) and blue (B) pixels. A transflective layer having a rate of about 50% is formed. Thereafter, similarly to the first embodiment, a hole injection / transport layer, an organic EL layer, a cathode, and the like are formed, and a sealing process is further performed to obtain the organic EL device 100 of the second embodiment.

(Third embodiment)
Next, a third embodiment of the organic EL device will be described with reference to FIG. In the third embodiment, unlike the first and second embodiments, two pixel electrodes are formed in one pixel in each of the green (G) and blue (B) pixels, and two pixel electrodes are formed accordingly. A TFT is formed. Note that the red (R) pixel has the same configuration as in the first and second embodiments, and the components different from those in the first and second embodiments will be described below.

  In the organic EL device 101 shown in FIG. 5, the green (G) and blue (B) pixels are each divided into two dots, and two pixel electrodes are formed in one pixel. The two pixel electrodes divided and formed in one pixel are a pixel electrode 127 having a red absorption filter function (hereinafter also referred to as a colored pixel electrode 127) and a pixel electrode 111 having no filter function. The TFTs 123 are connected to the pixel electrodes 127 and 111, respectively. The dots having the colored pixel electrode 127 and the dots having the pixel electrode 111 are partitioned by the bank 112, and the dots having the colored pixel electrode 127 are formed on the colored pixel electrode 127 as in the second embodiment. The semi-transmissive reflective layer 126 is formed, and the hole injection / transport layer 110a and the light emitting layer 110b are further formed. Note that the transflective layer is not formed on the pixel electrode 111, and the hole injection / transport layer 110a and the light emitting layer 110b are formed in the same manner as the red (R) pixel.

  In addition, the configuration of the cathode 12 and the like is the same as that of the first and second embodiments, and the same effect as that of the second embodiment can be exhibited in the configuration of the third embodiment. Further, according to the third embodiment, the brightness of display can be improved as compared with the configuration in which the transflective layer 126 is formed in the entire area of the green (G) and blue (B) pixels. . In addition, the structure which divides | segments one pixel into several dots like this 3rd Embodiment is employable also in the organic EL apparatus of the structure provided with the red absorption filter 125 like 1st Embodiment. Further, when dividing the pixels, it is not always necessary to divide the dots in the bank layer 112. For example, each dot is formed without a bank layer as in the organic EL device 102 shown in FIG. It is also possible. Furthermore, as a driving method, for example, when it is desired to produce a vivid color, it is preferable to drive only the dot including the transflective layer 126 among the green (G) and blue (B) pixels. On the other hand, in the case of displaying a light color or an intermediate color, both the dot having the transflective layer 126 and the dot not having the transflective layer 126 are selected from the green (G) and blue (B) pixels. It can be driven.

(Fourth embodiment)
FIG. 7 shows an embodiment of the electronic apparatus of the present invention.
The electronic apparatus of this example includes the above-described organic EL device as display means. FIG. 7 is a perspective view showing an example of a mobile phone. Reference numeral 1000 denotes a mobile phone main body, and reference numeral 1001 denotes a display unit using the organic EL device. As described above, an electronic apparatus including the organic EL device according to the electro-optical device of the present invention as a display unit can obtain good light emission characteristics and can reduce the price of the electronic apparatus.

Explanatory drawing which shows the structure of the organic electroluminescent apparatus of 1st Embodiment typically. The circuit diagram which shows the circuit structure of an active matrix type organic electroluminescent apparatus. The enlarged view which shows the cross-section of a display area | region about the organic electroluminescent apparatus of 1st Embodiment. The enlarged view which shows the cross-section of a display area | region about the organic electroluminescent apparatus of 2nd Embodiment. The enlarged view which shows the cross-section of a display area | region about the organic electroluminescent apparatus of 3rd Embodiment. The enlarged view which shows the cross-section of a display area about the modification of 3rd Embodiment. FIG. 14 is a perspective view showing an embodiment of an electronic apparatus according to the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 ... Organic EL apparatus, 12 ... Cathode (light reflective electrode), 110b ... Organic EL layer (light emitting layer), 111 ... Pixel electrode (anode, light transmissive electrode), 126 ... Semi-transmissive reflective layer

Claims (4)

A light reflective electrode;
A light transmissive electrode;
A light emitting layer formed between the light reflective electrode and the light transmissive electrode;
A bank layer having a pixel opening for forming the light emitting layer;
A transflective layer that transmits or reflects light from the light emitting layer only for green and blue pixels of the light transmissive electrode, and is provided on an insulating film formed on a substrate ,
The light emitting layer is disposed between the light reflective electrode and the transflective layer,
The optical distance between the light reflective electrode and the transflective layer is such that the transflective layer acts as an optical resonator between the transflective layer and the light reflective electrode. It is arranged at a position that is the same as the wavelength of light emitted from the light emitting layer or an integer multiple of the wavelength of the light,
The transflective layer is formed in a planar shape having an area equal to or larger than the pixel opening at a position overlapping the pixel opening in plan view, and the side surface of the transflective layer and the transflective layer The light emitting layer side surface is covered with the light transmissive electrode,
A red absorption filter that absorbs red is disposed between the insulating film and the transflective layer, and is disposed so as to cover a surface of the transflective layer on the light emission side. Organic EL device.   The organic EL device according to claim 1, wherein the light emitting layer has a thickness common to each pixel.   3. The organic EL device according to claim 1, wherein the hole injection / transport layer formed as a base of the light emitting layer has a thickness common to each pixel.   An electronic apparatus comprising the organic EL device according to claim 1.

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