JP2007200904A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To optimize the chromaticity of light in a light-emitting device having a luminous layer. <P>SOLUTION: The light-emitting device comprises the luminous layer 14 and an electrode layer 16. Light taken out of the light-emitting device includes light entering the electrode layer 16 from the luminous layer 14. The coating thickness of the electrode layer 16 (transmission layer 18) is determined so that the chromaticity of light when the light is taken out approaches a prescribed value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device and an electronic device including a light emitting layer.

  As a light emitting device including a light emitting layer, for example, there is an organic EL display device including an organic electroluminescence (hereinafter referred to as organic EL) element. In general, an organic EL element has an organic functional layer including a light emitting layer disposed between two opposing electrodes.

  When performing color display, the organic EL display device has a light emitting layer that emits light of a predetermined chromaticity for each of R (red), G (green), and B (blue) colors. On the substrate, light emitting layers corresponding to the respective colors are arranged in a predetermined arrangement.

  The chromaticity of light emitted from the light emitting layer can be obtained, for example, by appropriately selecting a material for forming the light emitting layer. However, when the chromaticity of the light when extracted is far from the target value, it is necessary to correct the chromaticity of the emitted light.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a light emitting device capable of optimizing light chromaticity and a method for manufacturing the same.
Another object of the present invention is to provide an electronic device with improved display performance.

As a result of intensive studies, the inventors of the present invention have a tendency that when light emitted from a light emitting layer is extracted after entering the electrode layer, the chromaticity of the light when it is extracted varies depending on the film thickness of the electrode layer. This problem was solved by determining the film thickness of the electrode layer so that the chromaticity of the light when taken out becomes a predetermined value.
That is, the light emitting device of the present invention includes a first electrode formed on a substrate, a first light emitting layer disposed above the first electrode, and a second electrode disposed above the first light emitting layer. A third electrode; a second light emitting layer disposed above the third electrode; a fourth electrode disposed above the second light emitting layer; and above the second electrode and the fourth electrode. A light emitting device comprising: a material layer disposed so as to cover the first light emitting layer and the second light emitting layer, wherein the first electrode comprises: a first reflective layer; the first light emitting layer; And a third transmissive layer provided between the first reflective layer and the third electrode. The third electrode is disposed between the second reflective layer, the second light emitting layer, and the second reflective layer. A laminated structure including a second transmissive layer provided, wherein the film thickness of the first transmissive layer is different from the film thickness of the second transmissive layer. .
The film thickness of the first light-emitting layer is determined according to the chromaticity of the light transmitted from the first light-emitting layer through at least the material layer, and the light emitted from the second light-emitting layer is at least the material. The thickness of the second light emitting layer is determined according to the chromaticity of light transmitted through the layer.
Furthermore, the light emitting device of the present invention includes a first electrode formed on the substrate, a first light emitting layer disposed above the first electrode, and a second electrode disposed above the first light emitting layer. A third electrode; a second light emitting layer disposed above the third electrode; a fourth electrode disposed above the second light emitting layer; and the second electrode comprising: a first reflective layer; , And a first transmissive layer provided between the first light emitting layer and the first reflective layer, wherein the fourth electrode includes the second reflective layer, the second light emitting layer, and the first light emitting layer. It has a laminated structure including a second transmission layer provided between the second reflection layer, and the film thickness of the first transmission layer is different from the film thickness of the second transmission layer.
Further, the film thickness of the first light emitting layer is determined according to the chromaticity of the light transmitted from the first light emitting layer through at least the substrate, and the light emitted from the second light emitting layer transmits at least the substrate. The thickness of the second light emitting layer is determined according to the chromaticity of the light.
According to the above light emitting device, the chromaticity of light can be optimized.

In the above light-emitting device, the light-emitting layer includes three types of light-emitting layers corresponding to three colors of red, green, and blue, and the electrode layer is a region in which light of the three types of light-emitting layers is incident. It is preferable that the film thickness is determined for each.
By determining the film thickness of each electrode layer corresponding to each color of red, green, and blue, the chromaticity of light can be optimized for each color.

In the above light emitting device, the electrode layer may include a plurality of stacked layers, and a film thickness of at least one of the plurality of layers may be determined.
For example, the plurality of layers may include a transmission layer that transmits light from the light emitting layer and a reflection layer that reflects the light, and the thickness of the transmission layer may be determined. In this case, part of the light from the light emitting layer passes through the transmissive layer, is reflected by the reflective layer, and is again taken out through the transmissive layer. By passing through the transmission layer, the chromaticity of the light is corrected, and the chromaticity of the light is optimized.

The electronic device includes the light-emitting device described above.
According to the above electronic device, since the above-described light emitting device is provided, the chromaticity of light is optimized and good display performance is obtained.

As a reference example, the above-described method for manufacturing a light emitting device includes a step of disposing a light emitting layer above a substrate, a step of disposing an electrode layer above the light emitting layer, and covering the light emitting layer above the electrode layer. And arranging the material layer in such a manner that the film thickness of the electrode layer is such that the chromaticity of the light when the light emitted from the light emitting layer is extracted through at least the material layer is a predetermined value. It is characterized by defining.
Alternatively, the method includes a step of disposing a light emitting layer above the substrate and a step of disposing an electrode layer above the light emitting layer, and light emitted from the light emitting layer is extracted at least through the substrate. The film thickness of the electrode layer is determined so that the chromaticity of light becomes a predetermined value.
According to said manufacturing method, the light-emitting device with favorable chromaticity of the light when taken out can be manufactured.

In the manufacturing method, the light emitting layer includes three types of light emitting layers corresponding to three colors of red, green, and blue, and the film thickness of the electrode layer is incident on the light of the three types of light emitting layers. It is preferable to define each region separately.
For the arrangement of the three types of light emitting layers, for example, a mask vapor deposition method may be used.
By determining the film thickness of each electrode layer corresponding to each color of red, green, and blue, the chromaticity can be optimized for each color.

The present invention will be described below with reference to the drawings. Note that in each drawing to be referred to, the scale may be different from the actual one in order to make the size recognizable on the drawing.
FIG. 1 is a diagram conceptually showing an organic EL display device according to an embodiment of a light emitting device of the present invention. In FIG. 1, an organic EL display device 10 includes a circuit element portion 12, a pixel electrode (anode) 13, an organic functional layer 15 including a light emitting layer 14, a counter electrode (cathode) 16, and a seal on a substrate 11 as a base. It has a structure in which stop portions 17 are sequentially stacked. Among these, an organic EL device (organic EL element) as an electro-optical element is configured including the anode 13, the functional layer 15, the cathode 16, and the like.
In addition, the code | symbol 29 shown in FIG. 1 is a bank layer as a partition member provided in the boundary of a pixel. The bank layer 29 has a role of preventing mixing of adjacent materials when forming the organic EL element.

In the organic EL display device, the holes injected from the anode side and the electrons injected from the cathode side recombine in the light emitting layer, and light is emitted via the excited state (light emission when the excited state is lost). Wake up. In addition, by appropriately selecting a material for forming the light emitting layer, emitted light having a predetermined chromaticity can be obtained. As a material for forming the light emitting layer, for example, a low molecular weight organic light emitting dye or a polymer light emitting material, that is, a light emitting material composed of various fluorescent materials or phosphorescent materials is used.
Note that layers having specific functions such as a hole injection layer, a hole transport layer, and an electron transport layer are appropriately formed between the anode and the light-emitting layer and between the cathode and the light-emitting layer, respectively. In addition, electrical control for light emission is performed through a circuit element unit including an active element or the like.

  The organic EL display device 10 shown in FIG. 1 is compatible with color display and emits three types of light emitting layers that emit light of chromaticity corresponding to three colors of red (R), green (G), and blue (B). 14 is included. In an organic EL display device, when performing color display, light emitting layers corresponding to R, G, and B colors are arranged on a substrate in a predetermined arrangement such as a stripe shape, a matrix shape (mosaic shape), or a delta shape. The The display device 10 is of a so-called back emission type in which the light emitted from the organic EL element is extracted from the substrate 11 side.

  In the back emission type organic EL display device 10, the light emitted from the light emitting layer 14 toward the substrate 11 is extracted through the substrate 11 as it is. On the other hand, the light emitted toward the side opposite to the substrate 11 side is reflected by the cathode 16, and then passes through the light emitting layer 14 and the like and is extracted from the substrate 11 side. That is, the light (observed light) extracted from the display device 10 includes light emitted from the beginning toward the substrate 11 and light reflected by the cathode 16.

Here, since the display device 10 is configured to extract light from the substrate 11 side, a transparent or translucent material is used as the substrate 11.
Similarly, a material for forming the anode 13 having transparency such as ITO is used.
The cathode 16 has a laminated structure including a transmission layer 18 that transmits light from the light emitting layer 14 and a reflection layer 19 that reflects the light. A transmissive layer 18 is disposed on the side close to the light emitting layer 14, and a reflective layer 19 is disposed outside thereof.
Of the light emitted from the light-emitting layer 14, the light incident on the cathode 16 is reflected by the reflective layer 19 after passing through the transmission layer 18 of the cathode 16. Thereafter, the light passes through the transmission layer 18 and the light emitting layer 14 and is taken out from the substrate 11 side.

  In the display device 10, the film thickness of the cathode 16 is determined so that the chromaticity of the light when it is extracted approaches a predetermined target value. More specifically, the film thickness of the transmissive layer 18 of the cathode 16 is individually determined for each region where the light of each of the three types of light emitting layers 14 of R, G, and B is incident.

The target value of chromaticity is, for example, a color that defines a color reproduction range of a CRT (cathode ray tube) so that each light of R, G, and B has color characteristics suitable for use in a full color display. Degrees are used.
As a method for determining the thickness of the transmission layer, for example, a plurality of types of display devices having different thicknesses of the transmission layer are prepared, and the chromaticity of light is measured. Then, the relationship between the film thickness of the transmission layer and the chromaticity of light is obtained for each color of R, G, and B from the measurement results, and based on the relationship, the chromaticity of light approaches a predetermined target value. The thickness of the transmission layer is determined.

By individually determining the film thickness of the transmission layer 18 on which R, G, and B light is incident, the chromaticity inherent to each light from the light emitting layer 14 is corrected. In the correction of chromaticity, a part of the wavelength of light is absorbed by passing through the transmissive layer 18, or light reflected by the surface of the transmissive layer 18 and reflected by the reflective layer 19 through the transmissive layer 18. It is thought to be caused by interference with light. Thereby, in this display apparatus 10, the chromaticity of light is optimized.
Note that the method of correcting the chromaticity according to the film thickness of the transmissive layer 18 does not use an element that causes a decrease in luminance, such as a color filter, and thus has an advantage of suppressing the decrease in luminance of light.

Here, examples of the transparent or translucent substrate include a glass substrate, a quartz substrate, a resin substrate (plastic substrate, plastic film substrate), and the like, and an inexpensive soda glass substrate is preferably used. When a soda glass substrate is used, by applying silica coating to the soda glass substrate, soda glass that is weak against acid-alkali is protected and the flatness of the substrate is improved.
Moreover, as an anode forming material, for example, a transparent electrode material such as ITO or IZO is used.

In addition, examples of the material for forming the cathode include aluminum (Al), magnesium (Mg), gold (Au), silver (Ag), and calcium (Ca), as well as ITO, IZO, lithium fluoride (LiF), and the like. Is mentioned.
Examples of the laminated structure including the transmissive layer and the reflective layer in the cathode 16 include a laminated film of Ca and Al (Ca / Al; transmissive layer / reflective layer), Mg / Ag, Ca / Ag, Ba / Ag, M / Ag (where M is at least one of rare earth elements, preferably at least one element of Ce, Yb, Sm, Er, Y, La, Gd (gadolinium), Dy (dysprosium), Nd (neodymium)) Etc. Further, a film made of LiF may be provided on the light emitting layer side (for example, LiF / Ca / Al). Note that when the cathode has a stacked structure, it is preferable to form a material having a small work function on the side close to the light emitting layer. The cathode in the present invention only needs to include at least a transmissive layer and a reflective layer, and is not limited to the above example. For example, at least one of the transmissive layer and the reflective layer may have a laminated structure.
Further, these cathodes are preferably formed by, for example, vapor deposition, sputtering, CVD, or the like, and in particular, it is preferable to form by a vapor deposition method in terms of preventing damage to the light emitting layer due to heat.
Further, a protective layer such as SiO ₂ or SiN may be provided on the cathode to prevent oxidation.

  The sealing portion 17 prevents water and oxygen from entering and prevents the cathode 16 or the functional layer 15 from being oxidized, and a sealing resin applied to the substrate 11 and a sealing bonded to the substrate 11. Includes substrates (sealing cans) and the like. 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 11 and is applied by, for example, a microdispenser. The sealing substrate is made of glass, metal, or the like, and the substrate 11 and the sealing substrate are bonded to each other via a sealing resin.

FIG. 2 is a diagram showing the results of examining the change in the chromaticity of blue (B) accompanying the change in the thickness of the cathode in the display device having the above configuration. A blue light emitting polymer was used as the light emitting layer, and a (LiF /) Ca / Al configuration was used as the cathode.
In FIG. 2, when (LiF: 2 nm /) Ca: 5 nm / Al: 200 nm, the emission chromaticity was (x, y) = (0.165,0.156), whereas (LiF: 2 nm /) Ca: When 20 nm / Al: 200 nm, the emission chromaticity is (x, y) = (0.169, 0.167), and the light chromaticity is set to the target value (TG) by changing the film thickness of Ca which is the transparent layer of the cathode. ) Was confirmed to be possible.

FIG. 3 is a diagram showing a result of examining a change in green (G) chromaticity accompanying a change in the thickness of the cathode in the display device having the above-described configuration. In addition, the green light emitting polymer was used for the light emitting layer, and the structure of Ca / Al was used for the cathode.
In FIG. 3, the emission chromaticity (x, y) = (0.41, 0.57) when Ca: 5 nm / Al: 200 nm, whereas the emission chromaticity (Ca: 20 nm / Al: 200 nm). x, y) = (0.42, 0.56), and it was confirmed that the chromaticity of light can be brought close to the target value (TG) by changing the film thickness of Ca which is the transparent layer of the cathode. It was.

  FIG. 4 shows another embodiment in which the light emitting device of the present invention is applied to an organic EL display device. The display device 50 emits light from the light emitting layer 14 from the side opposite to the substrate 11 on which the circuit element portion is provided. It consists of a so-called top emission type that extracts light. 4, components having the same functions as those of the display device 10 shown in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  In the top emission type organic EL display device 50, the light emitted from the light emitting layer 14 toward the substrate 11 is reflected by the anode 13, and then passes through the light emitting layer 14 to pass through the substrate 11. Taken from the opposite side. On the other hand, the light emitted toward the side opposite to the substrate 11 side passes through the cathode 16 and the like and is extracted. That is, the light extracted from the display device 50 includes light reflected by the anode 13 and light emitted from the beginning toward the opposite side to the substrate 11 side.

Here, since the display device 50 is configured to extract light from the side opposite to the substrate 11, the substrate may be transparent or opaque. Examples of the opaque substrate include a thermosetting resin and a thermoplastic resin in addition to a ceramic sheet such as alumina and a metal sheet such as stainless steel that has been subjected to an insulation treatment such as surface oxidation.
As the anode, one having transparency such as indium tin oxide (ITO) is used.
The anode 13 has a laminated structure including a transmission layer 51 that transmits light from the light emitting layer 14 and a reflection layer 52 that reflects the light. A transmissive layer 51 is disposed on the side close to the light emitting layer 14, and a reflective layer 52 is disposed outside thereof.
In addition, as a material for forming the cathode 16, a material having transparency is used.
Of the light emitted from the light emitting layer 14, the light incident on the anode 13 is reflected by the reflective layer 52 after passing through the transmission layer 51 of the anode 13. Thereafter, the light passes through the transmission layer 51, the light emitting layer 14, and the like, and is taken out from the substrate 11 side.

In the display device 50, unlike the display device 10 shown in FIG. 1, the film thickness of the anode 13 is determined so that the chromaticity of the light when taken out approaches a predetermined target value. More specifically, the film thickness of the transmission layer 51 of the anode 13 is individually determined for each region where light of each of the three types of light emitting layers 14 of R, G, and B is incident.
By individually determining the film thickness of the transmission layer 51 on which R, G, and B light is incident, the chromaticity inherent to each light from the light emitting layer 14 is corrected. Thereby, in this display apparatus 50, the chromaticity of light is optimized.
In the case of the top emission type, light is extracted from the opposite side of the substrate, so that the aperture ratio of the pixel can be increased.

  Note that the chromaticity of the light emitted from the light emitting layer can be corrected by changing the film thickness of the light emitting layer 14. For this reason, the thickness of the light emitting layer and the thickness of the electrode (cathode, anode) on which the light emitting layer is incident may be determined in combination so that the chromaticity of light further approaches the target value.

Next, the display device 10 shown in FIG. 1 will be described in more detail.
FIG. 5 shows an example of the circuit structure of the display device 10 described above, and FIG. 6 shows an example of the planar structure of the pixel portion in the display device 10.

  As shown in FIG. 5, the display device 10 includes a plurality of scanning lines 131, a plurality of signal lines 132 extending in a direction intersecting the scanning lines 131, and the signal lines 132 on a substrate as a base. A plurality of common power supply lines 133 extending in parallel are respectively wired, and a pixel (pixel area element) 102 is provided at each intersection of the scanning line 131 and the signal line 132.

  For the signal line 132, for example, a data side driving circuit 103 including a shift register, a level shifter, a video line, and an analog switch is provided. On the other hand, a scanning side drive circuit 104 including a shift register and a level shifter is provided for the scanning line 131. In each of the pixel regions 102, a first thin film transistor 142 to which a scanning signal is supplied to the gate electrode via the scanning line 131 and an image signal supplied from the signal line 132 via the first thin film transistor 142. , A second thin film transistor 143 to which an image signal held by the storage capacitor cap is supplied to the gate electrode, and the second thin film transistor 143 and the common power supply line 133 are electrically connected to each other. A pixel electrode (anode) 13 into which a driving current sometimes flows from the common power supply line 133 and a light emitting unit 140 (light emitting layer) disposed between the pixel electrode 13 and the counter electrode (cathode) 16 are provided. It has been.

  Further, as shown in FIG. 6, the planar structure of each pixel 102 is such that the four sides of the pixel electrode 13 having a rectangular planar shape are used for the signal line 132, the common power supply line 133, the scanning line 131, and other pixel electrodes (not shown). The arrangement is surrounded by scanning lines. As the planar shape of the pixel region 102, an arbitrary shape such as a circle or an oval is applied in addition to the rectangle shown in the figure.

  Under such a configuration, when the scanning line 131 is driven and the first thin film transistor 142 is turned on, the potential of the signal line 132 at that time is held in the holding capacitor cap, and the state depends on the state of the holding capacitor cap. Thus, the conduction state of the second thin film transistor 143 is determined. Then, a current flows from the common power supply line 133 to the pixel electrode 13 through the channel of the second thin film transistor 143, and further, a current flows to the counter electrode 16 through the light emitting unit 140, whereby the light emitting unit 140 has an amount of current flowing therethrough. In response to the light emission.

FIG. 7 shows an enlarged cross-sectional structure of the pixel portion 102 (organic EL element).
In FIG. 7, the organic EL element includes a substrate, an anode 13 (pixel electrode) made of a transparent electrode material, a hole injection layer (hole transport layer) 285 capable of injecting or transporting holes, and an electro-optical material. A light emitting layer 14 (organic EL layer) containing one organic EL material, a cathode 16 (counter electrode) provided on the upper surface of the light emitting layer 14, and a data signal to the anode 13 are formed on the substrate 11. Thin film transistors 142 and 143 are provided as energization control units for controlling whether to write data. An electron transport layer may be provided between the light emitting layer 14 and the cathode 16.

  In this example, the thin film transistors 142 and 143 are both formed in an n-channel type. Note that the thin film transistors 142 and 143 are not limited to n-channel TFTs, and p-channel thin film transistors may be used for both or one of them.

The thin film transistors 142 and 143 are provided on the surface of the substrate 11 via a base protective film 201 mainly composed of, for example, SiO _{2. The} thin film transistors 142 and 143 include semiconductor films 204 and 205 made of silicon or the like formed on the base protective film 201. The gate insulating film 220 provided in the upper layer of the base protective film 201 so as to cover the semiconductor films 204 and 205, and the gate electrode provided in a portion of the upper surface of the gate insulating film 220 facing the semiconductor films 204 and 205 229, 230, a first interlayer insulating film 250 provided on the gate insulating film 220 so as to cover the gate electrodes 229, 230, and a contact hole opened over the gate insulating film 220 and the first interlayer insulating film 250. The source electrodes 262 and 263 connected to the semiconductor films 204 and 205 through the gate electrodes 229 and 230 Drain electrodes 265 and 266 provided at positions facing the source electrodes 262 and 263 and connected to the semiconductor films 204 and 205 through contact holes that open through the gate insulating film 220 and the first interlayer insulating film 250, and source electrodes 262 and 263 and drain electrodes 265 and 266 are provided, and a second interlayer insulating film 270 provided on the first interlayer insulating film 250 is provided.

The pixel electrode (anode) 13 is disposed on the upper surface of the second interlayer insulating film 270, and the pixel electrode 13 and the drain electrode 266 are connected through a contact hole provided in the second interlayer insulating film 270. . Further, a third insulating layer (bank layer) 281 made of synthetic resin or the like is provided between a portion of the surface of the second interlayer insulating film 270 other than the portion where the organic EL element is provided and the cathode 16. Yes.
In FIG. 7, the bank layer 281 has a taper structure in which the length of the top side is smaller than the length of the bottom side. Conversely, the length of the top side is equal to or larger than the length of the bottom side. It may be a simple structure.
Further, when the materials of the first interlayer insulating film 250 and the second interlayer insulating film 270 are different from each other, as shown in the figure, the contact holes provided in the first interlayer insulating film 250 and the second interlayer insulating film 270 are provided. The contact hole 275 is preferably formed so as not to overlap.

  In addition, regions of the semiconductor films 204 and 205 that overlap with the gate electrodes 229 and 230 with the gate insulating film 220 interposed therebetween are channel regions 246 and 247. Further, in the semiconductor films 204 and 205, source regions 233 and 236 are provided on the source side of the channel regions 246 and 247, while drain regions 234 and 235 are provided on the drain side of the channel regions 246 and 247. ing. Among these, the source regions 233 and 236 are connected to the source electrodes 262 and 263 through contact holes that open through the gate insulating film 220 and the first interlayer insulating film 250. On the other hand, the drain regions 234 and 235 are connected to drain electrodes 265 and 266 that are formed in the same layer as the source electrodes 262 and 263 through contact holes that open through the gate insulating film 220 and the first interlayer insulating film 250. Yes. The pixel electrode 13 is electrically connected to the drain region 235 of the semiconductor film 205 through the drain electrode 266.

  Next, an embodiment in which the method for manufacturing a light emitting device of the present invention is applied to the above-described process for manufacturing the organic EL display device will be described with reference to FIGS. In this example, a process for simultaneously manufacturing an organic EL element including the above-described thin film transistors 142 and 143 and a thin film transistor for N-type and P-type driving circuits will be described.

  First, as shown in FIG. 8A, a substrate 11 is formed of a silicon oxide film having a thickness of about 200 to 500 nm by plasma CVD using TEOS (tetraethoxysilane) or oxygen gas as a raw material as necessary. A base protective film 201 is formed. In addition to the silicon oxide film, a silicon nitride film or a silicon oxynitride film may be provided as the base protective film. By providing such an insulating film, heat dissipation can be improved.

Next, the temperature of the substrate 11 is set to about 350 ° C., and a semiconductor film 200 made of an amorphous silicon film having a thickness of about 30 to 70 nm is formed on the surface of the base protective film using an ICVD method, a plasma CVD method, or the like. To do. The semiconductor film 200 is not limited to an amorphous silicon film, and may be a semiconductor film including an amorphous structure such as a microcrystalline semiconductor film. Alternatively, a compound semiconductor film including an amorphous structure such as an amorphous silicon germanium film may be used.
Subsequently, a crystallization process such as a laser annealing method or a rapid heating method (such as a lamp annealing method or a thermal annealing method) is performed on the semiconductor film 200 to crystallize the semiconductor film 200 into a polysilicon film. In the laser annealing method, for example, a line beam having a beam length of 400 mm is used with an excimer laser, and the output intensity is set to 200 mJ / cm ² , for example. Note that the second harmonic or the third harmonic of the YAG laser may be used. As for the line beam, it is preferable to scan the line beam so that a portion corresponding to 90% of the peak value of the laser intensity in the short dimension direction overlaps each region.

Next, as shown in FIG. 8B, unnecessary portions of the semiconductor film (polysilicon film) 200 are removed by patterning using a photolithography method or the like, and corresponding to each formation region of the thin film transistor, Island-shaped semiconductor films 202, 203, 204, and 205 are formed.
Subsequently, a gate insulating film 220 made of a silicon oxide film or a nitride film (silicon oxynitride film or the like) having a thickness of about 60 to 150 nm is formed so as to cover the semiconductor film 200 by plasma CVD using TEOS or oxygen gas as a raw material. To do. The gate insulating film 220 may have a single layer structure or a stacked structure. In addition, you may use other methods, such as not only a plasma CVD method but a thermal oxidation method. In addition, when the gate insulating film 220 is formed using a thermal oxidation method, the semiconductor film 200 is also crystallized, and these semiconductor films can be formed into a polysilicon film.

Next, as shown in FIG. 8C, a gate electrode forming conductive film containing doped silicon, a silicide film, or a metal such as aluminum, tantalum, molybdenum, titanium, or tungsten on the entire surface of the gate insulating film 220. 221 is formed. The thickness of the conductive film 221 is, for example, about 200 nm.
Subsequently, a patterning mask 222 is formed on the surface of the gate electrode forming conductive film 221, and patterning is performed in this state. As shown in FIG. 8D, the P-type driver circuit transistor is formed. Then, a gate electrode 223 is formed. At this time, since the gate electrode forming conductive film 221 is covered with the patterning mask 222 on the side of the N-type pixel electrode transistor and the N-type driver circuit transistor, the gate electrode forming conductive film 221 is patterned. It will never be done. In addition, the gate electrode may be formed using a single-layer conductive film or a stacked structure.

Next, as shown in FIG. 8E, the gate electrode 223 of the P-type driving circuit transistor, the region where the N-type pixel electrode transistor is formed, and the N-type driving circuit transistor are formed. Using the gate electrode forming conductive film 221 left in the region as a mask, a p-type impurity element (boron in this example) is ion-implanted. The dose amount is, for example, about 1 × 10 15 cm ⁻² . As a result, high-concentration source / drain regions 224 and 225 having an impurity concentration of, for example, 1 × 10 20 cm ⁻³ are formed in a self-aligned manner with respect to the gate electrode 223. Here, a portion which is covered with the gate electrode 223 and no impurity is introduced becomes a channel region 226.

  Next, as shown in FIG. 9A, the P-type driving circuit transistor side is completely covered, and the N-type pixel electrode TFT 10 and the N-type driving circuit transistor side gate electrode formation are formed. A patterning mask 227 made of a resist mask or the like covering the region is formed.

Next, as shown in FIG. 9B, the patterning mask 227 is used to pattern the gate electrode forming conductive film 221 so that the N-type pixel electrode transistor and the N-type driver circuit transistor gate electrode are patterned. 228, 229, 230 are formed.
Subsequently, an n-type impurity element (phosphorus in this example) is ion-implanted while the patterning mask 227 remains. The dose amount is, for example, 1 × 10 15 cm ⁻² . As a result, impurities are introduced in a self-aligned manner with respect to the patterning mask 227, and high concentration source / drain regions 231, 232, 233, 234, 235, 236 are formed in the semiconductor films 203, 204, 205. . Here, in the semiconductor films 203, 204, and 205, a region where high concentration phosphorus is not introduced is wider than a region covered with the gate electrodes 228, 229, and 230. That is, in the semiconductor films 203, 204, and 205, high concentration between the high concentration source / drain regions 231, 232, 233, 234, 235, and 236 is on both sides of the region facing the gate electrodes 228, 229, and 230. A region where low phosphorus is not introduced (low concentration source / drain regions described later) is formed.

Next, the patterning mask 227 is removed, and an n-type impurity element (phosphorus in this example) is ion-implanted in this state. The dose amount is 1 × 10 13 cm ⁻² , for example. As a result, as shown in FIG. 9C, low concentration impurities are introduced into the semiconductor films 203, 204, and 205 in a self-aligned manner with respect to the gate electrodes 228, 229, and 230. 237, 238, 239, 240, 241, 242 are formed. Note that impurities are not introduced into regions overlapping with the gate electrodes 228, 229, and 230, and channel regions 245, 246, and 247 are formed.

Next, as shown in FIG. 9D, a first interlayer insulating film 250 is formed on the surface side of the gate electrodes 228, 229, and 230, and is patterned by a photolithography method or the like to form predetermined source electrode positions and drain electrodes. A contact hole is formed at the position. As the first interlayer insulating film 250, for example, an insulating film containing silicon such as a silicon oxynitride film or a silicon oxide film may be used. Further, it may be a single layer or a laminated film. Further, heat treatment is performed in an atmosphere containing hydrogen to terminate the dangling bonds of the semiconductor film with hydrogen (hydrogenation). Note that hydrogenation may be performed using hydrogen excited by plasma.
Subsequently, a conductive film 251 to be a source electrode and a drain electrode is formed from above using a metal film such as an aluminum film, a chromium film, or a tantalum film. The thickness of the conductive film 251 is, for example, about 200 nm to 300 nm. The conductive film may be a single layer or a laminated film.
Subsequently, a patterning mask 252 is formed at the positions of the source electrode and the drain electrode, and patterning is performed, so that the source electrodes 260, 261, 262, and 263 and the drain electrodes 264, 265, and 266 shown in FIG. Are formed at the same time.

  Next, as shown in FIG. 10A, a second interlayer insulating film 270 made of silicon nitride or the like is formed. The thickness of the second interlayer insulating film 270 is, for example, about 1 to 2 μm. As a material for forming the second interlayer insulating film 270, a material capable of transmitting light, such as a silicon oxide film, an organic resin, or silica airgel, is used. As the organic resin, acrylic, polyimide, polyamide, BCB (benzocyclobutene), or the like can be used.

  Next, as shown in FIG. 10B, the second interlayer insulating film 270 is removed by etching to form a contact hole 275 reaching the drain electrode 266.

Next, as shown in FIG. 10C, a film made of, for example, SnO ₂ doped with ITO or fluorine, and a transparent electrode material such as ZnO or polyaniline is formed so as to be embedded in the contact hole 275 as well. Then, the pixel electrode 13 electrically connected to the source / drain regions 235 and 236 is formed. The pixel electrode 13 serves as an anode of the EL element.

  Next, as shown in FIG. 11A, a third insulating layer (bank layer) 29 is formed so as to sandwich the pixel electrode 13. Specifically, for example, a resist such as acrylic resin or polyimide resin melted in a solvent is applied by spin coating, dip coating or the like to form an insulating layer, and the insulating layer is simultaneously etched by photolithography technology or the like. To do. As the third insulating layer 29, a synthetic resin such as an acrylic resin or a polyimide resin is used. Note that a bank layer including wiring such as signal lines, common power supply lines, and scanning lines may be formed.

Subsequently, a hole injection layer 285 is formed so as to cover the pixel electrode 13.
In this example, the hole injection layer 285 is formed using a droplet discharge device that discharges the forming material as droplets. That is, the material for forming the hole injection layer 285 is discharged from the nozzle 114 toward the substrate 11. By placing a predetermined amount of material on the substrate 11, the hole injection layer 285 is formed on the substrate 11.

  In addition, when the material becomes liquid on the substrate 11, it spreads in the horizontal direction due to its fluidity, but the spread is prevented by the partition walls of the third insulating layer (bank layer). Note that in the case where inconvenience due to material flow does not occur due to processing conditions, material characteristics, or the like, the height of the third insulating layer may be reduced, or a structure without a partition may be employed. Further, after discharging the material from the nozzle 114 onto the substrate 11, the material may be solidified or cured by performing a treatment such as heating or light irradiation on the substrate 11 as necessary.

  As a material for forming the hole injection layer, for example, PEDT / PSS which is a mixture of polyethylene dioxythiophene and polystyrene sulfonic acid is desirably used. Other examples include a mixture of polyaniline and polystyrene sulfonic acid and copper phthalocyanine (CuPc). In the case of forming both a hole injection layer and a hole transport layer in a low molecular weight organic EL device or the like, for example, the hole injection layer is formed on the pixel electrode side prior to the formation of the hole transport layer, A hole transport layer is preferably formed thereon. By forming the hole injection layer together with the hole transport layer in this manner, it is possible to control the increase in driving voltage and to increase the driving life (half life).

Next, as shown in FIG. 11B, the light emitting layer 14 is formed on the hole injection layer 285.
In this example, the light emitting layer 14 is formed by using the above-described droplet discharge device, similarly to the previous hole injection layer. That is, the material for forming the light emitting layer 14 is discharged as droplets from the nozzle 114 toward the substrate 11.

As the material for forming the light-emitting layer 14, a polymer light emitter can be used, and a polymer having a light-emitting group in the side chain can be used, but preferably contains a conjugated structure in the main chain, Polyfluorene, poly-p-phenylene vinylene, polythiophene, polyarylene vinylene, and derivatives thereof are preferred. Of these, polyarylene vinylene and its derivatives are preferred. The polyarylene vinylene and its derivatives are polymers containing 50 mol% or more of the repeating units represented by the following chemical formula (1) based on the total repeating units. Although it depends on the structure of the repeating unit, it is more preferable that the repeating unit represented by the chemical formula (1) is 70% or more of the entire repeating unit.
-Ar-CR = CR'- (1)
[Wherein Ar is an arylene group or heterocyclic compound group having 4 to 20 carbon atoms involved in the conjugated bond, R and R ′ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms. , A group selected from the group consisting of an aryl group having 6 to 20 carbon atoms, a heterocyclic compound having 4 to 20 carbon atoms, and a cyano group. ]

  The polymeric fluorescent substance includes an aromatic compound group or a derivative thereof, a heterocyclic compound group or a derivative thereof, and a group obtained by combining them as a repeating unit other than the repeating unit represented by the chemical formula (1). May be. In addition, the repeating unit represented by the chemical formula (1) and other repeating units may be linked by a non-conjugated unit having an ether group, an ester group, an amide group, an imide group, or the like, Non-conjugated moieties may be included.

  In the polymer fluorescent substance, Ar in the chemical formula (1) is an arylene group or a heterocyclic compound group having 4 to 20 carbon atoms involved in the conjugated bond, and is represented by the following chemical formula (2). Examples include an aromatic compound group or a derivative group thereof, a heterocyclic compound group or a derivative group thereof, and a group obtained by combining them. In the low molecular organic EL device, low molecular phosphors such as naphthalene derivatives, anthracene derivatives, perylene derivatives, dyes such as polymethine, xanthene, coumarin, and cyanine, and metal complexes of 8-hydroquinoline and its derivatives. , Aromatic amines, tetraphenylcyclopentadiene derivatives and the like, or known ones described in JP-A-57-51781 and 59-194393 can be used.

  The material for forming the electron transport layer is not particularly limited, and is an oxadiazole derivative, anthraquinodimethane and its derivative, benzoquinone and its derivative, naphthoquinone and its derivative, anthraquinone and its derivative, tetracyanoanthraquinodimethane And derivatives thereof, fluorenone derivatives, diphenyldicyanoethylene and derivatives thereof, diphenoquinone derivatives, metal complexes of 8-hydroxyquinoline and derivatives thereof, and the like. Specifically, as with the material for forming the hole transport layer, JP-A-63-70257, JP-A-63-175860, JP-A-2-135359, JP-A-2-135361, and JP-A-2-209888 are disclosed. And the like described in JP-A-3-379992 and 3-152184, particularly 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4. -Oxadiazole, benzoquinone, anthraquinone, tris (8-quinolinol) aluminum are preferred.

  Note that a material for forming the hole injection layer (hole transport layer) or a material for forming the electron transport layer may be mixed with the material for forming the light emitting layer 14 and used as the light emitting layer forming material. In that case, although the amount of the hole transport layer forming material or electron transport layer forming material used varies depending on the type of compound used, etc., it should be considered within an amount range that does not impair sufficient film formability and light emission characteristics. To be determined as appropriate. Usually, it is 1 to 40 weight% with respect to the light emitting layer forming material, More preferably, it is 2 to 30 weight%.

Next, as shown in FIG. 11C, the counter electrode 16 as a cathode is formed on the entire surface of the substrate 11 or in a stripe shape. As described above, the counter electrode 16 is formed by sequentially laminating the transmissive layer 18 that transmits light and the reflective layer 19 that reflects light.
At this time, the film thickness of the transmissive layer 18 is changed for each region where light of the three types of light emitting layers corresponding to the three colors of red, green, and blue is incident. Such a layer can be formed, for example, by using a mask vapor deposition method. That is, the cathode forming material is vapor-deposited through a mask, and the vapor deposition time may be changed for each region.

  Through the above process, an organic EL element and a thin film transistor for N-type and P-type drive circuits are completed.

  Here, the above chemical formula (2) is shown.

（Ｒ１〜Ｒ９２は、それぞれ独立に、水素、炭素数１〜２０のアルキル基、アルコキシ基およびアルキルチオ基；炭素数６〜１８のアリール基およびアリールオキシ基；ならびに炭素数４〜１４の複素環化合物基からなる群から選ばれた基である。）

(R1 to R92 are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkoxy group and an alkylthio group; an aryl group and aryloxy group having 6 to 18 carbon atoms; and a heterocyclic compound having 4 to 14 carbon atoms. A group selected from the group consisting of groups.)

  Among these, phenylene group, substituted phenylene group, biphenylene group, substituted biphenylene group, naphthalenediyl group, substituted naphthalenediyl group, anthracene-9,10-diyl group, substituted anthracene-9,10-diyl group, pyridine-2, 5-diyl group, substituted pyridine-2,5-diyl group, thienylene group and substituted thienylene group are preferred. More preferred are a phenylene group, a biphenylene group, a naphthalenediyl group, a pyridine-2,5-diyl group, and a thienylene group.

  When R and R ′ in the chemical formula (1) are hydrogen or a substituent other than a cyano group, the alkyl group having 1 to 20 carbon atoms includes a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group. Hexyl group, heptyl group, octyl group, decyl group, lauryl group and the like, and methyl group, ethyl group, pentyl group, hexyl group, heptyl group and octyl group are preferable. Examples of the aryl group include a phenyl group, a 4-C1-C12 alkoxyphenyl group (C1-C12 indicates that the number of carbon atoms is 1-12, and the same shall apply hereinafter), a 4-C1-C12 alkylphenyl group, 1 -A naphthyl group, 2-naphthyl group, etc. are illustrated.

  From the viewpoint of solvent solubility, Ar in the chemical formula (1) is one or more alkyl groups having 4 to 20 carbon atoms, alkoxy groups and alkylthio groups, aryl groups and aryloxy groups having 6 to 18 carbon atoms, and 4 to 4 carbon atoms. It preferably has a group selected from 14 heterocyclic compound groups.

  Examples of these substituents are as follows. Examples of the alkyl group having 4 to 20 carbon atoms include a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and a lauryl group, and a pentyl group, a hexyl group, a heptyl group, and an octyl group are preferable. Examples of the alkoxy group having 4 to 20 carbon atoms include a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, a lauryloxy group, and the like, such as a pentyloxy group and a hexyloxy group. , A heptyloxy group and an octyloxy group are preferable. Examples of the alkylthio group having 4 to 20 carbon atoms include a butylthio group, a pentylthio group, a hexylthio group, a heptylthio group, an octylthio group, a decyloxy group, and a laurylthio group, and a pentylthio group, a hexylthio group, a heptylthio group, and an octylthio group are preferable. Examples of the aryl group include a phenyl group, a 4-C1-C12 alkoxyphenyl group, a 4-C1-C12 alkylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. A phenoxy group is illustrated as an aryloxy group. Examples of the heterocyclic compound group include a 2-thienyl group, 2-pyrrolyl group, 2-furyl group, 2-, 3- or 4-pyridyl group. The number of these substituents varies depending on the molecular weight of the polymeric fluorescent substance and the constitution of the repeating unit, but from the viewpoint of obtaining a highly soluble polymeric fluorescent substance, these substituents are one or more per 600 molecular weight. It is more preferable.

  The polymeric fluorescent substance may be a random, block or graft copolymer, or may be a polymer having an intermediate structure thereof, for example, a random copolymer having a block property. . From the viewpoint of obtaining a polymer fluorescent substance having a high fluorescence quantum yield, a random copolymer having a block property and a block or graft copolymer are preferable to a complete random copolymer. Moreover, since the organic electroluminescent element formed here utilizes fluorescence from a thin film, the polymer fluorescent substance having fluorescence in a solid state is used.

When a solvent is used for the polymeric fluorescent substance, preferred examples include chloroform, methylene chloride, dichloroethane, tetrahydrofuran, toluene, xylene and the like. Although depending on the structure and molecular weight of the polymeric fluorescent substance, it can usually be dissolved in these solvents in an amount of 0.1 wt% or more.
Moreover, as said polymeric fluorescent substance, it is preferable that molecular weight is 103-107 in polystyrene conversion, Their polymerization degree changes also with a repeating structure and its ratio. In general, the total number of repeating structures is preferably 4 to 10000, more preferably 5 to 3000, and particularly preferably 10 to 2000 from the viewpoint of film formability.

  The method for synthesizing such a polymeric fluorescent substance is not particularly limited. For example, a dialdehyde compound in which two aldehyde groups are bonded to an arylene group, a compound in which two halogenated methyl groups are bonded to an arylene group, and triphenyl A Wittig reaction from a diphosphonium salt obtained from phosphine is exemplified. As another synthesis method, a dehydrohalogenation method from a compound in which two halogenated methyl groups are bonded to an arylene group is exemplified. Further, a sulfonium salt decomposition method for obtaining the polymeric fluorescent substance by heat treatment from an intermediate obtained by polymerizing a sulfonium salt of a compound having two halogenated methyl groups bonded to an arylene group with an alkali is exemplified. In any of the synthesis methods, a compound having a skeleton other than an arylene group is added as a monomer, and by changing the abundance ratio, the structure of the repeating unit contained in the generated polymeric fluorescent substance can be changed. The repeating unit represented by (1) may be added and adjusted so as to be 50 mol% or more and copolymerized. Among these, the method by Wittig reaction is preferable in terms of reaction control and yield.

More specifically, a method for synthesizing an arylene vinylene copolymer, which is one example of the polymeric fluorescent substance, will be described. For example, when obtaining a polymeric fluorescent substance by Wittig reaction, for example, first, a bis (halogenated methyl) compound, more specifically, for example, 2,5-dioctyloxy-p-xylylene dibromide is converted to N, N- A phosphonium salt is synthesized by reacting with triphenylphosphine in a dimethylformamide solvent, and this is condensed with a dialdehyde compound, more specifically, for example, terephthalaldehyde using, for example, lithium ethoxide in ethyl alcohol. By the Wittig reaction, a polymeric fluorescent substance containing a phenylene vinylene group and a 2,5-dioctyloxy-p-phenylene vinylene group is obtained. At this time, in order to obtain a copolymer, two or more kinds of diphosphonium salts and / or two or more kinds of dialdehyde compounds may be reacted.
When these polymeric fluorescent substances are used as a material for forming a light emitting layer, the purity affects the light emission characteristics. Therefore, it is desirable to carry out a purification treatment such as reprecipitation purification and fractionation by chromatography after synthesis.
As the material for forming the light emitting layer made of the above-described polymeric fluorescent material, light emitting layer forming materials of three colors of red, green, and blue are used for full color display.

Further, when the light emitting layer described above is formed, the material may be formed of a host / guest light emitting material, that is, a light emitting material in which a guest material is added and dispersed in the host material.
As such a light emitting material, for example, a high molecular organic compound or a low molecular weight material as a host material, or a fluorescent dye or a phosphorescent material for changing the light emitting characteristics of a light emitting layer obtained as a guest material is used. Preferably used.
As the polymer organic compound, in the case of a material having low solubility, for example, after a precursor is applied, the polymer organic compound becomes a conjugated polymer organic electroluminescence layer by being heated and cured as shown in the following chemical formula (3). Some can produce a light emitting layer. For example, in the case of a sulfonium salt as a precursor, there are those in which a sulfonium group is eliminated by heat treatment to become a conjugated polymer organic compound.
In addition, some highly soluble materials can be used as a light emitting layer by applying the material as it is and then removing the solvent.

  The polymer organic compound is solid and has strong fluorescence, and can form a uniform solid ultrathin film. In addition, it has high forming ability and high adhesion to the ITO electrode, and further, after solidification, forms a strong conjugated polymer film.

As such a high molecular organic compound, for example, polyarylene vinylene is preferable. Since polyarylene vinylene is soluble in an aqueous solvent or an organic solvent, it can be easily prepared into a coating solution when applied to the second substrate 11, and can be polymerized under certain conditions. A high-quality thin film can be obtained.
Examples of such polyarylene vinylene include PPV (poly (para-phenylene vinylene)), MO-PPV (poly (2,5-dimethoxy-1,4-phenylene vinylene)), CN-PPV (poly (2,5 -Bishexyloxy-1,4-phenylene- (1-cyanovinylene))), MEH-PPV (poly [2-methoxy-5- (2′-ethylhexyloxy)]-para-phenylenevinylene), etc. , Poly (alkylthiophene) such as PTV (poly (2,5-thienylenevinylene)), PFV (poly (2,5-furylenevinylene)), poly (paraphenylene), polyalkylfluorene, and the like. Among them, those composed of precursors of PPV or PPV derivatives as shown in chemical formula (4), and polymers as shown in chemical formula (5) Rukirufluorene (specifically, a polyalkylfluorene copolymer as shown in chemical formula (6)) is particularly preferred.
Since PPV or the like is a conductive polymer having strong fluorescence and π electrons forming a double bond being nonpolarized on the polymer chain, a high-performance organic electroluminescence device can be obtained.

In addition to the PPV thin film, a high molecular organic compound or a low molecular material capable of forming a light emitting layer, that is, a material used as a host material in this example includes, for example, an aluminum quinolinol complex (Alq ₃ ), distyryl biphenyl, In addition to BeBq ₂ and Zn (OXZ) ₂ shown in (7) and those conventionally used such as TPD, ALO, and DPVBi, pyrazoline dimer, quinolidinecarboxylic acid, benzopyrylium perchlorate, Examples include benzopyranoquinolizine, rubrene, phenanthroline europium complex, and the like, and a composition for an organic electroluminescence device containing one or more of these can be used.

  On the other hand, examples of the guest material added to such a host material include fluorescent dyes and phosphorescent substances as described above. In particular, the fluorescent dye can change the light emission characteristics of the light emitting layer, and is effective, for example, as a means for improving the light emission efficiency of the light emitting layer or changing the light absorption maximum wavelength (light emission color). That is, the fluorescent dye can be used not only as a light emitting layer material but also as a dye material having a light emitting function itself. For example, the energy of exciton generated by carrier recombination on a conjugated polymer organic compound molecule can be transferred onto the fluorescent dye molecule. In this case, since light emission occurs only from fluorescent dye molecules having high fluorescence quantum efficiency, the current quantum efficiency of the light emitting layer is also increased. Therefore, by adding a fluorescent dye to the material for forming the light emitting layer, the emission spectrum of the light emitting layer simultaneously becomes that of the fluorescent molecule, which is effective as a means for changing the emission color.

The current quantum efficiency here is a scale for considering the light emission performance based on the light emission function, and is defined by the following equation.
ηE = energy of emitted photons / input electric energy And, by converting the light absorption maximum wavelength by doping with a fluorescent dye, it is possible to emit, for example, three primary colors of red, blue and green, resulting in a full color display It becomes possible.
Furthermore, the luminous efficiency of the electroluminescence element can be significantly improved by doping with a fluorescent dye.

  As the fluorescent dye, in the case of forming a light emitting layer that emits red colored light, it is preferable to use the laser dye DCM-1, rhodamine or rhodamine derivative, penylene, or the like. A light emitting layer can be formed by doping a host material such as PPV with these fluorescent dyes. However, since many of these fluorescent dyes are water-soluble, they are added to a sulfonium salt that is a water-soluble PPV precursor. Doping and then heat treatment makes it possible to form a more uniform light emitting layer. Specific examples of such fluorescent dyes include rhodamine B, rhodamine B base, rhodamine 6G, rhodamine 101 perchlorate and the like, and a mixture of two or more thereof may be used.

  In the case of forming a light emitting layer that emits green colored light, it is preferable to use quinacridone, rubrene, DCJT and derivatives thereof. For these fluorescent dyes, a light emitting layer can be formed by doping a host material such as PPV as in the case of the above fluorescent dyes. However, since these fluorescent dyes are often water-soluble, they are water-soluble. If a sulfonium salt, which is a PPV precursor, is doped and then heat-treated, a more uniform light emitting layer can be formed.

  Furthermore, when forming a light emitting layer that emits blue colored light, it is preferable to use distyrylbiphenyl and its derivatives. For these fluorescent dyes, a light emitting layer can be formed by doping a host material such as PPV as in the case of the above fluorescent dyes. However, since these fluorescent dyes are often water-soluble, they are water-soluble. If a sulfonium salt, which is a PPV precursor, is doped and then heat-treated, a more uniform light emitting layer can be formed.

  In addition, examples of other fluorescent dyes having blue colored light include coumarin and derivatives thereof. These fluorescent dyes are compatible with PPV and can easily form a light emitting layer. Among these, particularly, coumarin is insoluble in a solvent itself, but there are some which become soluble in a solvent by increasing the solubility by appropriately selecting a substituent. Specific examples of such fluorescent dyes include coumarin-1, coumarin-6, coumarin-7, coumarin 120, coumarin 138, coumarin 152, coumarin 153, coumarin 311, coumarin 314, coumarin 334, coumarin 337, coumarin 343 and the like. Is mentioned.

Furthermore, examples of the fluorescent dye having another blue colored light include tetraphenylbutadiene (TPB) or a TPB derivative, DPVBi, and the like. These fluorescent dyes are soluble in an aqueous solution in the same manner as the red fluorescent dye and the like, have good compatibility with PPV, and can easily form a light emitting layer.
About the above fluorescent dye, only 1 type may be used for each color, and 2 or more types may be mixed and used for it.
In addition, as such a fluorescent dye, those shown in chemical formula (8), those shown in chemical formula (9), and those shown in chemical formula (10) are used.

  About these fluorescent dyes, it is preferable to add 0.5-10 wt% by the method mentioned later with respect to the host material consisting of the said conjugated polymer organic compound etc., and adding 1.0-5.0 wt%. More preferred. If the amount of fluorescent dye added is too large, it will be difficult to maintain the weather resistance and durability of the light-emitting layer obtained. On the other hand, if the amount added is too small, the effects of adding the fluorescent dye as described above will be sufficiently obtained. Because there is no.

In addition, Ir (ppy) ₃ , Pt (thpy) ₂ , PtOEP, or the like represented by the chemical formula (11) is preferably used as a phosphorescent material as a guest material added to the host material.

Note that when the phosphor represented by the chemical formula (11) is used as a guest material, CBP, DCTA, TCPB, and the above-described DPVBi, Alq ₃ shown in the chemical formula (12) are particularly preferably used as the host material. .
Further, both the fluorescent dye and the phosphor may be added to the host material as a guest material.

  When the above-described light emitting layer is formed using such a host / guest luminescent material, the host material and the guest material are simultaneously ejected at a preset ratio so that a desired amount of guest material is applied to the host material. A light emitting layer can be formed using a light emitting material to which is added.

  In the above-described example, the hole transport layer is formed as the lower layer of the light emitting layer, and the electron transport layer is formed as the upper layer. However, the present invention is not limited to this, for example, the hole transport layer and the electron transport layer. May be formed, or a hole injection layer may be formed instead of the hole transport layer, and only the light emitting layer may be formed alone. Good.

  Furthermore, in addition to the hole injection layer, the hole transport layer, the light emitting layer, and the electron transport layer, a hole blocking layer may be formed, for example, on the counter electrode side of the light emitting layer to extend the life of the light emitting layer. As a material for forming such a hole blocking layer, for example, BCP represented by the chemical formula (13) and BAlq represented by the chemical formula (14) are used, but BAlq is preferable in terms of extending the life.

12-17 has shown the Example of the electronic device of this invention.
The electronic apparatus of this example includes the light emitting device of the present invention such as the organic EL display device described above as a display unit.
FIG. 12 shows an example of a display device that displays television images and characters and images sent to a computer. In FIG. 12, reference numeral 1000 denotes a display device body using the light emitting device of the present invention. In addition, the display apparatus main body 1000 can respond also to a large screen by using the organic EL display apparatus mentioned above.
FIG. 13 shows an example of a vehicle-mounted navigation device. In FIG. 13, reference numeral 1010 indicates a navigation apparatus body, and reference numeral 1011 indicates a display unit (display means) using the light-emitting device of the present invention.
FIG. 14 shows an example of a portable image recording apparatus (video camera). In FIG. 14, reference numeral 1020 denotes a recording apparatus main body, and reference numeral 1021 denotes a display portion using the light emitting device of the present invention.
FIG. 15 shows an example of a mobile phone. In FIG. 15, reference numeral 1030 indicates a mobile phone body, and reference numeral 1031 indicates a display unit (display means) using the light emitting device of the present invention.
FIG. 16 shows an example of an information processing apparatus such as a word processor or a personal computer. In FIG. 16, reference numeral 1040 denotes an information processing apparatus, reference numeral 1041 denotes an information processing apparatus body, reference numeral 1042 denotes an input unit such as a keyboard, and reference numeral 1043 denotes a display unit using the light emitting device of the present invention.
FIG. 17 shows an example of a wristwatch type electronic device. In FIG. 17, reference numeral 1050 indicates a watch body, and reference numeral 1051 indicates a display unit using the light emitting device of the present invention.
Since the electronic devices shown in FIGS. 12 to 17 include the light emitting device of the present invention as display means, the chromaticity of light can be optimized and good display performance can be obtained.

  As mentioned above, although the suitable Example concerning this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  According to the light emitting device of the present invention, the chromaticity of the light can be optimized by determining the film thickness of the electrode layer on which the light from the light emitting layer is incident.

  Moreover, according to the method for manufacturing a light emitting device of the present invention, a light emitting device with optimized light chromaticity can be manufactured.

  In addition, according to the electronic apparatus of the present invention, since the light emitting device with optimized light chromaticity is provided, display performance can be improved.

It is a figure which shows notionally the organic electroluminescent display apparatus which concerns on one Embodiment of the light-emitting device of this invention. It is a figure which shows the result of having investigated the change of chromaticity (blue) accompanying the change of the film thickness of a cathode. It is a figure which shows the result of having investigated the change of chromaticity (green) accompanying the change of the film thickness of a cathode. It is a figure which shows notionally another form example which applied the light-emitting device of this invention to the organic electroluminescence display. It is a circuit diagram which shows an example of the circuit structure of an organic electroluminescence display. It is a top view which shows an example of the planar structure of the pixel part in an organic electroluminescence display. It is a figure which expands and shows the cross-section of a pixel part (organic EL element). It is a figure for demonstrating the Example which applied the manufacturing method of the electro-optical apparatus of this invention to the process of manufacturing a display apparatus provided with an organic EL element. It is a figure for demonstrating the Example which applied the manufacturing method of the electro-optical apparatus of this invention to the process of manufacturing a display apparatus provided with an organic EL element. It is a figure for demonstrating the Example which applied the manufacturing method of the electro-optical apparatus of this invention to the process of manufacturing a display apparatus provided with an organic EL element. It is a figure for demonstrating the Example which applied the manufacturing method of the electro-optical apparatus of this invention to the process of manufacturing a display apparatus provided with an organic EL element. It is a figure which shows the Example of the electronic device of this invention. It is a figure which shows the other Example of the electronic device of this invention. It is a figure which shows the other Example of the electronic device of this invention. It is a figure which shows the other Example of the electronic device of this invention. It is a figure which shows the other Example of the electronic device of this invention. It is a figure which shows the other Example of the electronic device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Organic EL display device (light emitting device), 11 ... Substrate, 13 ... Anode (pixel electrode, electrode layer), 14 ... Light emitting layer, 16 ... Cathode (counter electrode, electrode layer), 18 ... Transmission layer, 19 ... Reflection layer.

Claims (4)

A first electrode formed on the substrate;
A first light emitting layer disposed above the first electrode;
A second electrode disposed above the first light emitting layer;
A third electrode;
A second light emitting layer disposed above the third electrode;
A fourth electrode disposed above the second light emitting layer;
A light emitting device comprising: a material layer disposed so as to cover the first light emitting layer and the second light emitting layer above the second electrode and the fourth electrode,
The first electrode has a laminated structure including a first reflective layer and a first transmission layer provided between the first light emitting layer and the first reflective layer,
The third electrode has a laminated structure including a second reflective layer and a second transmissive layer provided between the second light emitting layer and the second reflective layer,
The light emitting device, wherein the film thickness of the first transmission layer is different from the film thickness of the second transmission layer.   The film thickness of the first light emitting layer is determined according to at least the chromaticity of the light emitted from the first light emitting layer and transmitted through the material layer, and the light emitted from the second light emitting layer passes through at least the material layer. The light emitting device according to claim 1, wherein a film thickness of the second light emitting layer is determined according to a chromaticity of transmitted light. A first electrode formed on the substrate;
A first light emitting layer disposed above the first electrode;
A second electrode disposed above the first light emitting layer;
A third electrode;
A second light emitting layer disposed above the third electrode;
A fourth electrode disposed above the second light emitting layer;
The second electrode has a laminated structure including a first reflective layer and a first transmission layer provided between the first light emitting layer and the first reflective layer,
The fourth electrode has a laminated structure including a second reflective layer, and a second transmissive layer provided between the second light emitting layer and the second reflective layer,
The light emitting device, wherein the film thickness of the first transmission layer is different from the film thickness of the second transmission layer.   The film thickness of the first light emitting layer is determined according to at least the chromaticity of the light emitted from the first light emitting layer and transmitted through the substrate, and the light emitted from the second light emitting layer is transmitted through at least the substrate. The light emitting device according to claim 3, wherein a film thickness of the second light emitting layer is determined according to chromaticity of the light emitting layer.

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