JP2006196237A - Electroluminescence drive displace device and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroluminescence drive display device with reduced power consumption, capable of securing visibility, even when it is used as an outdoor mobile display, and to provide its manufacturing method. <P>SOLUTION: In an electroluminescent light-emitting part, consisting of a plurality of light-emitting layers 104, 106, 108 pinched between both electrodes of a cathode 101 and an anode 111, transport layers 105, 107, 109 are installed at upper parts of respective light-emitting layers, and gate electrodes 112, 113, 114 are formed in the respective transport layers. Furthermore, three or more layers of the light-emitting layers are preferably provided, where each light-emitting layer is doped with a luminescent organic material so that the value of the energy band gap of the luminescent organic material, in each light-emitting layer, becomes larger sequentially starting from the cathode 101 side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electroluminescence driving display device and a manufacturing method thereof. Electroluminescence with a built-in vertical TFT that can produce full-color light emission suitable for monitors, TVs, etc., characterized by improved outdoor visibility, low power consumption, and improved lifespan, especially with a single drive voltage The present invention relates to a drive display device and a manufacturing method thereof.

  In recent years, electroluminescent devices having a plurality of light emitting layers having different wavelengths have been developed. The structure shown in Patent Document 1 is shown in FIG. An anode 1 is formed by sputtering ITO (indium-tin oxide) on a transparent glass substrate 10 having a thickness of 0.7 mm, and a hole transport layer 11 is formed on the ITO anode 1 by a vacuum deposition apparatus. On the hole transport layer 11, the host layer “DPVBi” is doped with 1% by mass of the dopant “BCzVBi” to form an organic light emitting material 3a of a blue light emitting layer, and “Alq3” is evaporated thereon to form an electron. The transport layer 12 is formed, and the cathode 2 is formed.

Similarly, an organic light emitting material 3b that emits green light is formed by vapor-depositing a host layer “Alq3” doped with 1% by mass of a dopant “Coumarin 6” on the hole transport layer 11. “Alq3” is deposited thereon to form the electron transport layer 12, and the cathode 2 is formed. Further, after the hole transport layer 11 is formed, a red light emitting material 3c is formed by vapor-depositing a host layer “Alq3” doped with 1% by mass of a dopant “DCJTB”. “Alq 3” is deposited thereon to form the electron transport layer 12, and the cathode 2 is formed.
JP 2002-164170 A

  In the display device, since each pixel is formed in a stripe shape, there is a first drawback that a blue + green + red full-color electroluminescence display portion becomes large. Further, when an organic electroluminescence (EL) element is used as a mobile display, there is a second drawback that visibility is poor outdoors because it is self-luminous. Furthermore, when the energization current is increased to improve the visibility, the power consumption increases, and there is a third drawback that the life is shortened in proportion to the increase of the energization current.

  In consideration of such conventional drawbacks, the present invention provides an electroluminescence driving display device that can ensure visibility even when used as an outdoor mobile display and has reduced power consumption, and a method for manufacturing the same.

  In order to solve the above-mentioned problems, in the present invention of claim 1, in the electroluminescent light-emitting portion comprising a plurality of light-emitting layers sandwiched between both the cathode and the anode, a transport layer is provided above each light-emitting layer. A gate electrode was formed in each of the transport layers.

  According to the second aspect of the present invention, in the electroluminescence light-emitting portion comprising a plurality of light-emitting layers sandwiched between both the cathode and the anode, a transport layer is provided above each light-emitting layer, A plurality of gate electrodes were formed in a staggered pattern.

  In the present invention of claim 3, the light emitting layer is provided with three or more light emitting layers, and each light emitting layer is doped with the light emitting organic material so that the energy band gap value of the light emitting organic material increases in order from the cathode side.

  In the present invention of claim 4, the light emitting layer is provided with three or more light emitting layers, and each light emitting layer is doped with a light emitting organic material such that the energy band gap value of the light emitting organic material increases in order from the cathode side, and a band is interposed between the light emitting layers. The light emitting layer with the smallest gap was sandwiched.

  In the present invention of claim 5, the electroluminescent light emitting part is an electron transport layer, a light emitting layer 1, a transport layer 1, a light emitting layer 2, a transport layer 2, a light emitting layer 3, a transport layer 3, and a hole between the cathode and the anode. Consists of a transport layer.

  In the present invention of claim 6, the light emitting layer 1 is red, the light emitting layer 2 is green, and the light emitting layer 3 is blue.

  In the present invention of claim 7, the light emitting layer 1 is green, the light emitting layer 2 is red, and the light emitting layer 3 is blue.

  In the present invention of claim 8, the light emitting layer contains "Alq3".

  In the present invention of claim 9, the light emitting layers have different emission spectra.

  In this invention of Claim 10, luminescent color is blue light, green light, and red light by the combination of the said light emitting layer.

  In the present invention of claim 11, the light emission color is white light by the combination of the light emitting layers.

  In the present invention of claim 12, the light quantity of the light emitting layer is adjusted by changing the width of the transport layer sandwiched between the light emitting layers.

  In the present invention of claim 13, on the substrate, in the electroluminescent light emitting part comprising a plurality of light emitting layers sandwiched between the source electrode and the drain electrode, both electrodes, a transport layer is provided above each light emitting layer, A gate electrode was formed in each of the transport layers.

  According to the present invention of claim 14, in the electroluminescent light emitting part comprising a plurality of light emitting layers sandwiched between a source electrode and a drain electrode and both electrodes on a substrate, each light emitting layer is an energy band of a light emitting organic material. The light-emitting organic material was doped so that the gap value increased in order from the source electrode side.

  According to the present invention of claim 15, in the electroluminescence light-emitting part comprising a plurality of light-emitting layers sandwiched between a source electrode and a drain electrode and both electrodes on a substrate, each light-emitting layer is an energy band of a light-emitting organic substance. The light-emitting organic material was doped so that the gap value increased in order from the source electrode side, and the light-emitting layer with the smallest band gap was sandwiched therebetween.

  According to the present invention of claim 16, the electroluminescent light emitting part includes an electron transport layer, a light emitting layer 1, a transport layer 1, a light emitting layer 2, a transport layer 2, a light emitting layer 3, and a transport layer 3 between a source electrode and a drain electrode. And a hole transport layer.

  In the present invention of claim 17, the light emitting layer 1 is red, the light emitting layer 2 is green, and the light emitting layer 3 is blue.

  In the present invention of claim 18, the light emitting layer 1 is green, the light emitting layer 2 is red, and the light emitting layer 3 is blue.

  In the present invention of claim 19, the light emitting layer contains "Alq3".

  In the present invention of claim 20, the light emitting layers have different emission spectra.

  In the present invention of claim 21, the emission color is blue light, green light, or red light by the combination of the light emitting layers.

  In the present invention of claim 22, the emission color is white light by the combination of the light emitting layers.

  In the present invention of claim 23, the light quantity of the light emitting layer is adjusted by changing the width of the transport layer sandwiched between the light emitting layers.

  In the present invention of claim 24, the cathode or the source electrode is formed of a light transmissive electrode.

  In the present invention of claim 25, the anode or drain electrode is formed on the entire surface of the display portion and is formed of a metal electrode.

  In the present invention of claim 26, the anode or drain electrode is formed on the entire surface of the display portion to form a protective layer.

  According to the present invention of claim 27, in the electroluminescence light-emitting portion comprising a plurality of light-emitting layers sandwiched between the cathode and the anode, a transport layer is provided above each light-emitting layer, Then, a gate electrode was formed and light was extracted from the cathode side.

  In the present invention of claim 28, on the substrate, in the electroluminescent light emitting part comprising a plurality of light emitting layers sandwiched between a source electrode and a drain electrode, both electrodes, a transport layer is provided above each light emitting layer, A gate electrode is formed in each of the transport layers, and light is extracted from the substrate side.

  According to the 29th aspect of the present invention, in the electroluminescence light emitting section comprising a source electrode or a cathode, a drain electrode or an anode, and a plurality of light emitting layers sandwiched between both electrodes on the substrate, the source electrode or the cathode The same drive voltage was applied between the drain electrode and the anode.

  According to the present invention of claim 30, in the electroluminescent light emitting part comprising a source electrode or a cathode, a drain electrode or an anode, and a plurality of light emitting layers sandwiched between both electrodes on the substrate, the source electrode or the cathode The same driving current was applied between the drain electrode and the anode.

  In the present invention of Claim 31, a step of forming a plurality of light emitting layers sandwiched between a source electrode or a cathode, a drain electrode or an anode, and both electrodes on a substrate, and a transport layer above each light emitting layer A step of forming a gate electrode in each of the transport layers, a step of forming the source electrode or the cathode with a light transmissive metal layer, and a step of forming the drain electrode or the anode with a metal layer. It consists of.

  In the present invention of claim 32, the cathode is formed by sputtering, and the anode is formed by vapor deposition.

  In the present invention of Claim 33, the source electrode is formed by sputtering, and the drain electrode is formed by vapor deposition.

  According to the electroluminescence driving display device and the manufacturing method thereof of the present invention, the light emitting layer can be selected by forming the transport layer on the plurality of light emitting layers, and the light emitting region can be designated by the shape of the transport layer. Higher definition can be achieved by reducing the space between the light emitting portions by the transport layer.

Further, by inserting a gate electrode into these transport layers, light extraction efficiency can be increased by controlling recombination of electrons and holes and extracting light from the substrate side or the cathode side. As a result, a light semi-transmissive layer and a light reflecting layer are formed by the gate electrode, and can be used with increased visibility even outdoors.
Furthermore, by controlling the width of each transport layer, it is possible to improve the chromaticity characteristics when full color light is emitted. Each light emitting layer is always biased by a voltage applied to the source electrode (cathode) and the drain electrode (anode). As a result, each light emitting layer is energized for the same time, whereby a display portion with little color shift can be formed.

  In addition, the structure of the light emitting portion in which a plurality of layers are stacked can improve the life and reduce power consumption, and can provide an electroluminescence driving display device that can be used with a single driving voltage and a method for manufacturing the same.

  Hereinafter, according to the cross-sectional view of FIG. 1, an electroluminescence drive display device 100 according to the best mode 1 for carrying out the present invention will be described. In FIG. 1, an IZO (indium zinc oxide) transparent cathode 102 is formed on a glass substrate 101 by sputtering. Lithium fluoride “LiF” is deposited on the IZO transparent cathode 102 with a thickness of 5 mm, and “PBD” with LUMO 2.6 eV and HOMO 6.3 eV energy band gap 3.7 eV is deposited on the lithium fluoride with a thickness of 200 mm. A transport layer 103 is formed.

  Next, on the electron transport layer 103, a host layer “Alq3” doped with 1 wt% red dopant “DCJTB” with LUMO 3.2 eV, HOMO 5.3 eV energy band gap 2.1 eV was deposited to a thickness of 200 mm. A red light emitting layer 104 is formed.

  On the red light emitting layer 104, “NBP” is deposited to a thickness of 200 mm using the mask 1 as shown in FIG. 1, and a hole transport layer 1 (105 MOMO with a LUMO of 2.45 eV, a HOMO of 5.46 eV, and an energy band gap of 3.0 eV). ). On the hole transport layer 1 (105), a gate 1 (112) made of Al is formed using a mask 2. On the gate 1 (112), a mask 1 is used for vapor deposition to a thickness of 200 to form an upper portion of the hole transport layer 1 (105) having LUMO 2.45 eV, HOMO 5.46 eV, and energy band gap 3.0 eV.

  On top of the hole transport layer 1 (105), a 500 Å green light emitting layer 106 is deposited by doping the host layer “Alq3” with 1% by weight of a green dopant “Coumarin 6” with an LUMO of 2.9 eV and a HOMO of 5.3 eV and an energy band gap of 2.36 eV. To form. On the green light emitting layer 106, “NBP” is deposited to a thickness of 200 mm using the mask 3 as shown in FIG. 1 to form the lower portion of the hole transport layer 2 (107).

  On the hole transport layer 2 (107), a gate 2 (113) of Al is formed using a mask 4. On the lower part of the gate 2 (113), the upper part of the hole transport layer 2 (107) is formed by vapor deposition to a thickness of 200 mm using the mask 3. On top of the hole transport layer 2 (107), a host layer “BAlq” with an LUMO of 2.6 eV, a HOMO of 5.3 eV and an energy band gap of 2.7 eV doped with 1% by weight of a dopant “Perylene” is deposited to a thickness of 500 mm. Then, the blue light emitting layer 107 is formed from a blue light emitting organic light emitting material.

  On the blue light emitting layer 107, “NBP” is deposited to a thickness of 200 to form a lower portion of the hole transport layer 3 (109) having LUMO 2.3V, HOMO 5.5 eV, and energy band gap 3.2 eV. On the lower part of the hole transport layer 3 (109), a gate 3 (114) made of Al is formed using a mask 6.

  On the gate 3 (114), the upper part of the hole transport layer 3 (109) is formed by vapor deposition to a thickness of 200 mm using the mask 5. Next, a hole transport layer 110 made of MTDATA is formed on the hole transport layer 3 (109). “CuPc” is deposited to a thickness of 20 nm on the hole transport layer 110 to form an anode 111 on the “CuPc”.

  An anode 111 made of a metal electrode having a film thickness of about 0.4 μm is formed by vacuum deposition using Pt, Rh, Pd or the like. The present invention is characterized in that the anode 111 is formed of a metal layer. Another feature is that light is extracted from the substrate 101 side through the cathode 102.

  Since light is extracted to the outside from the substrate 101 side, the external extraction efficiency of light is increased. Here, when a negative voltage is applied to the cathode 102 and a positive voltage is applied to the anode 111, electrons transported to the light emitting layers 104, 106, and 108 through the electron transport layer 103 and holes transported through the hole transport layer 110 are generated. The red light emitting layer 104, the green light emitting layer 106, and the blue light emitting layer 108 are recombined to emit light.

  Here, in the full color electroluminescence driving display device 100 of the present invention, in the light emitting portions 104, 106, 108 formed in three layers, the LUMO band gap energy difference between the light emitting layer host layer and the dopant is 0.3 eV or more. Therefore, the dopant layer emits light.

  Further, the hole transport layer 1 (105), the hole transport layer 2 (107), and the hole transport layer 3 (109) are sandwiched between the three light emitting layers. Between each light emitting layer, there are two “Alq3” layers sandwiching the hole transport layer 1 (105), and further one “BAlq” layer sandwiching the hole transport layer 2 (107) and the hole transport layer 3 (109). It is characterized by being continuously formed by each organic substance.

  Since the hole transport layer 1 (105), the hole transport layer 2 (107), and the hole transport layer 3 (109) do not pass electrons through holes, electrons do not move upward in the lower portion of the hole transport layer 1 (105). Since the holes travel through the hole transport layer 1 (105) to the cathode 102, the electrons from the cathode 102 and the holes that have passed through the hole transport layer 1 (105) recombine at the bottom of the hole transport layer 1 (105). Therefore, the red light emitting layer 104 emits red light below the hole transport layer 1 (105).

  The hole transport layer 2 (107) does not pass electrons injected from the cathode. Since the hole transport layer 2 (107) allows the holes transported to the anode 111 to pass therethrough, the green light emitting layer 106 emits green light at a portion below the hole transport layer 2 (107) excluding the hole transport layer 1 (105).

  Electrons injected from the cathode 102 travel toward the anode 111, but the hole transport layer 3 (109) does not pass electrons. Since holes injected from the anode 111 pass through the hole transport layer 3 (109), the blue light-emitting layer 108 is recombined with electrons and holes below the hole transport layer 3 (109) except for the hole transport layer 2 (107). Emits blue light.

  A blue material has a larger energy band gap than other green and red materials, and thus tends to deteriorate charge injection. The present invention (high energy barrier for charge injection) is characterized in that the blue light emitting layer 108 having a large energy band gap is disposed under the hole transport layer 110 below the anode 111.

  Since it is located under the hole transport layer 110, the charge injection of the blue light emitting layer 108 does not deteriorate. Further, since the host layers of the green and red light emitting layers formed under the blue light emitting layer are made of the same or similar electron transport layer material as the electron transport layer 103, the electron transport is also efficient.

  In addition, each light emitting layer is formed in multiple layers, but this layer is selected where layers having different emission colors are selected from the hole transport layer 1 (105), the hole transport layer 2 (107), and the hole transport layer 3 (109). There is a feature of the invention. Also in the red light emitting layer 104 farthest from the anode 111, holes are transported through the hole transport layer 110, the hole transport layer 3 (109), and the hole transport layer 2 (107). An electron transport layer 103 is provided below the red light emitting layer 104, and electrons are transported so that recombination efficiency is good.

  Therefore, in FIG. 1, red light 117, green light 116, and blue light 115 are extracted from the substrate 101 side. Compared to the case where red, green, and blue are obtained using a color filter and a white light-emitting layer, since there is no absorption by the color filter, about three times the brightness can be obtained. In addition, the same amount of light can be obtained with a current of about 1/3 when a conventional white light emitting layer is used.

  Further, by forming the three layers in an overlapping manner, the variation in the luminous efficiency due to the decrease in the variation in the film thickness compared with the variation in the film thickness of the single-layer electroluminescent element is improved. Current consumption and lifetime variation are improved by reducing the current consumption to 1/3. Since the driving voltage also has three layers overlapping with the white element obtained by emitting blue, green, and red separately, a single voltage is sufficient, and driving is easier and the circuit can be omitted compared to the conventional FIG.

  Moreover, since the light is emitted solidly compared to the white element obtained by individually emitting blue, green, and red in FIG. 3, for example, it is not necessary to set the light emission width to 0.5 mm and the pitch to 0.5 mm. The area can be halved. As a result, the same amount of light emission can be obtained in a half area, so that high definition and high luminance can be achieved.

  Further, the second feature of the present invention is that the hole transport layer 1 (105), the hole transport layer 2 (107), and the hole transport layer 3 (109) have a gate electrode 1 (112), a gate electrode as shown in FIG. 2 (113) and gate electrode 3 (114) are formed.

  The cathode 102 also functions as a source electrode, and the anode 111 also functions as a drain electrode. The source electrode 102, the drain electrode 111 and the gate electrode 1 (112), the gate electrode 2 (113), and the gate electrode 3 (114) operate as a vertical TFT. There is a feature.

  Biased by the voltages applied to the source electrode 103 and the drain electrode 111 and applied to the gate electrode 1 (112), the gate electrode 2 (113), and the gate electrode 3 (114), the red light 117, the green light 116, The output of the blue light 115 is controlled. For this reason, the same current flows regardless of the emission color, so that the color difference due to changes over time becomes inconspicuous.

  Next, an electroluminescence drive display device 200 according to the best mode 2 for carrying out the present invention will be described with reference to the cross-sectional view of FIG. In FIG. 2, an IZO (indium zinc oxide) transparent cathode 102 is formed on a glass substrate 101 by sputtering. Lithium fluoride “LiF” is deposited on the IZO transparent cathode 102 with a thickness of 5 mm, and “PBD” with LUMO 2.6 eV and HOMO 6.3 eV energy band gap 3.7 eV is deposited on the lithium fluoride with a thickness of 200 mm. A transport layer 103 is formed.

  Next, on the electron transport layer 103, a host layer “Alq3” doped with 1 wt% red dopant “DCJTB” with LUMO 3.2 eV, HOMO 5.3 eV energy band gap 2.1 eV was deposited to a thickness of 200 mm. A red light emitting layer 104 is formed.

  On the red light emitting layer 104, “NBP” is deposited to a thickness of 150 mm using the mask 1 as shown in FIG. 2, and a hole transport layer 4 (205) having LUMO 2.45 eV, HOMO 5.46 eV, and energy band gap 3.0 eV. Form the lower part of. A gate 4 (212) made of Al is formed on the hole transport layer 4 (205) using a mask 7.

  On the gate 4 (212), the inside of the hole transport layer 4 (205) having a LUMO of 2.45 eV, a HOMO of 5.46 eV, and an energy band gap of 3.0 eV is formed by using the mask 1 to form a 130-mm thick film. On the upper part of the center of the hole transport layer 4 (205), a gate 1 (112) made of Al is formed using a mask 2.

  On the gate 1 (112), the upper part of the hole transport layer 4 (205) having a LUMO of 2.45 eV, a HOMO of 5.46 eV, and an energy band gap of 3.0 eV is formed by using the mask 1 to form a 130-mm thick film. On top of the hole transport layer 4 (205), a green light emitting layer 106 in which the host layer “Alq3” is doped with 1% by weight of a green dopant “Coumarin 6” with LUMO 2.9 eV and HOMO 5.3 eV energy band gap 2.36 eV is 500 μm. It is formed by vapor deposition.

  On the green light emitting layer 106, “NBP” is deposited to a thickness of 130 mm using a mask 8 as shown in FIG. 2 to form the lower portion of the hole transport layer 5 (207). A gate 2 (113) made of Al is formed on the hole transport layer 5 (207) using the mask 4.

  On the gate 2 (113), a central portion of the hole transport layer 5 (207) is formed by vapor deposition with a thickness of 130 mm using the mask 3. On the center of the hole transport layer 5 (207), a gate 2 (113) made of Al is formed using a mask 4. On the gate 2 (113), the upper part of the hole transport layer 5 (207) is formed by vapor deposition to a thickness of 130 mm using the mask 8.

  On top of the hole transport layer 5 (207), a host layer “BAlq” with LUMO 2.6 eV, HOMO 5.3 eV energy band gap 2.7 eV, doped with 1% by weight of dopant “Perylene” is deposited to a thickness of 500 mm. Then, the blue light emitting layer 107 is formed from a blue light emitting organic light emitting material.

  On the blue light emitting layer 107, “NBP” is deposited to a thickness of 130 to form a lower portion of the hole transport layer 6 (209) having LUMO of 2.3 V, HOMO of 5.5 eV, and an energy band gap of 3.2 eV. On the lower portion of the hole transport layer 6 (209), a gate 6 (214) made of Al is formed using a mask 9.

  On the gate 6 (214), a central portion of the hole transport layer 6 (209) is formed by vapor deposition to a thickness of 130 mm using the mask 5. On the center of the hole transport layer 6 (209), a gate 6 (214) made of Al is formed using a mask 9.

  On the gate 6 (214), the upper part of the hole transport layer 6 (209) is formed by vapor deposition to a thickness of 130 mm using the mask 5. A hole transport layer 110 made of MTDATA is formed on the hole transport layer 6 (209). “CuPc” is deposited to a thickness of 20 nm on the hole transport layer 110 to form an anode 111 on the “CuPc”.

  An anode 111 made of a metal electrode having a film thickness of about 0.4 μm such as Pt, Rh, Pd, etc. is formed by vacuum deposition. In the present invention, since the anode 111 is formed of a metal layer and is formed by vapor deposition, the light emitting layer is not damaged during the formation.

  Another feature is that light from the substrate 101 side is extracted to the outside through the cathode 102. Since light is extracted to the outside from the substrate 101 side, the external extraction efficiency of light is increased. Here, when a negative voltage is applied to the cathode 102 and a positive voltage is applied to the anode 111, electrons transported to the light emitting layers 104, 106, and 108 through the electron transport layer 103 and holes transported through the hole transport layer 110 are generated. The red light emitting layer 104, the green light emitting layer 106, and the blue light emitting layer 108 are recombined to emit light.

  Here, in the full-color electroluminescence driving display device 200 of the present invention, in the light emitting portions 104, 106, 108 formed in three layers, the LUMO band gap energy difference between the light emitting layer and the dopant is 0.3 eV or more. Become. Therefore, the dopant layer emits light.

  Further, the hole transport layer 4 (205), the hole transport layer 5 (207), and the hole transport layer 6 (209) are sandwiched between the three light emitting layers. Each light emitting layer is composed of two layers of “Alq3” with a hole transport layer 4 (205) in between, and one layer of “BAlq” and a hole transport layer 6 (209) with a hole transport layer 5 (207) in between. It is characterized by being formed continuously.

  The hole transport layer 4 (205), the hole transport layer 5 (207), and the hole transport layer 6 (209) do not pass electrons through holes. Therefore, electrons do not move upward in the lower part of 205, and the holes travel to the cathode 102 through the hole transport layer 4 (205). As a result, the electrons from the cathode 102 and the holes that have passed through the hole transport layer 4 (205) recombine at the bottom of the hole transport layer 4 (205), so that the red light emitting layer 104 is below the hole transport layer 4 (205). Emits red light.

  The hole transport layer 5 (207) does not pass electrons injected from the cathode 102. Since the hole transport layer 5 (207) allows holes transported from the anode 111 to pass through, the green light emitting layer 106 emits green light at a portion below the hole transport layer 5 (207) except for the hole transport layer 4 (205).

  Electrons injected from the cathode 102 travel toward the anode 111, but the hole transport layer 6 (209) does not pass electrons. Since the holes injected from the anode 111 pass through the hole transport layer 6 (209), the blue light-emitting layer 108 is recombined with electrons and holes below the hole transport layer 6 (209) except for the hole transport layer 5 (207). Emits blue light.

  The blue material has a larger energy band gap than other green and red materials, and therefore, charge injection tends to be poor. (High energy barrier for charge injection) The present invention is characterized in that the blue light emitting layer 108 having a large energy band gap is disposed under the hole transport layer 110 under the anode 111.

  Since it is located under the hole transport layer 110, charge injection does not deteriorate. Further, since the host layers of the green and red light emitting layers formed below the blue light emitting layer are made of the same or similar electron transport layer material as the electron transport layer 103, the electron transport is also efficient.

  In addition, each light emitting layer is formed in multiple layers, but this layer is selected where layers having different emission colors are selected from the hole transport layer 4 (205), the hole transport layer 5 (207), and the hole transport layer 6 (209). There is a feature of the invention.

  Also in the red light emitting layer 104 farthest from the anode 111, the hole transport layer 110, the hole transport layer 6 (209), and the hole transport layer 5 (207) are passed. Holes are transported, and an electron transport layer 103 is provided below the red light emitting layer 104. Since electrons are transported, the recombination efficiency is high. Therefore, in FIG. 2, red light 217, green light 216, and blue light 215 are extracted from the substrate 101 side, and there is no absorption by the color filter as compared with the case where red, green, and blue are obtained using a color filter and a white light emitting layer. Therefore, about three times the brightness can be obtained.

  The same amount of light can be obtained with about a third of the current when a conventional white light emitting layer is used. Further, by forming the three layers in an overlapping manner, the variation in the luminous efficiency due to the reduction in the variation in the film thickness as compared with the variation in the film thickness of the single-layer electroluminescent element is improved. And since current consumption becomes 1/3, current variation and life variation are improved. The driving voltage can be a single voltage because the three layers overlap with the white element obtained by emitting blue, green and red light separately, and the driving can be simplified and the circuit can be omitted as compared with the conventional FIG.

  Further, since the light is emitted solidly as compared with the white element obtained by individually emitting blue, green, and red in FIG. 3, for example, it is not necessary to set the light emission width to 0.5 mm and the pitch to 0.5 mm. Therefore, the light emission area can be halved. As a result, the same amount of light emission can be obtained in an area of ½, so that high definition and high luminance can be achieved.

  Further, the second feature of the present invention shown in FIG. 2 is that the hole transport layer 4 (205), the hole transport layer 5 (207), and the hole transport layer 6 (209) have a gate electrode 4 (212) as shown in FIG. The gate electrode 1 (112), the gate electrode 5 (213), the gate electrode 2 (113), the gate electrode 6 (214), and the gate electrode 3 (114) are alternately formed in a staggered manner by Al. Thus, it is characterized in that it works as a light reflecting layer in addition to the gate electrode.

  The cathode 102 also functions as a source electrode, and the anode 111 also functions as a drain electrode. Source electrode 102, drain electrode 111 and gate electrode 4 (212), gate electrode 1 (112), gate electrode 5 (213), gate electrode 2 (113), gate electrode 6 (214), and gate electrode 3 (114) Operates as a vertical TFT. The gate electrode 4 (212), the gate electrode 1 (112), the gate electrode 5 (213), the gate electrode 2 (113), the gate electrode 6 (214), biased by the voltage applied to the source electrode 103 and the drain electrode 111, The outputs of the red light 117, the green light 116, and the blue light 115 are controlled by the voltage applied to the gate electrode 3 (114).

  In FIG. 1 and FIG. 2, since the gaps between the pixels are not formed, the blue + green + red full-color electroluminescence display portion can be made small and high definition can be achieved. When the electroluminescence display unit 100 shown in FIG. 1 is used outdoors as a mobile display, the gate electrodes 1 to 3 serve as a light reflection layer. The gate electrode 1 to the gate electrode form a light transflective display portion, thereby improving visibility.

  When the display device 200 shown in FIG. 2 is used outdoors as a mobile display, the gate electrode 1 to the gate electrode 6 are formed in a staggered manner to form a light reflection type display portion, thereby further improving the visibility. be able to.

  As described above, the display devices 100 and 200 of FIGS. 1 and 2 are self-luminous, and unlike the LCD, a backlight is not required indoors or outdoors, so that power consumption can be reduced. Further, it is possible to improve visibility by forming a transflective display unit with the display device 100 in FIG. 1 and a reflective display unit with the display device 200 in FIG. For this reason, since the current can be reduced without increasing the current, the power consumption can be reduced. Further, by forming the three layers in an overlapping manner, the film thickness variation is smaller than the film thickness variation of the single-layer electroluminescent element. As a result, the light emission efficiency variation is improved, and the current consumption and the life variation are improved by reducing the current consumption to 1/3.

  Thus, in the present invention, it is possible to provide an electroluminescence driving display device which can be used as a mobile display by improving visibility and can reduce power consumption, and a manufacturing method thereof.

  Next, an electroluminescence drive display device according to the best mode 3 for carrying out the present invention will be described with reference to FIGS. 1 and 2, the light-emitting layer 104 is described as a red light-emitting layer, and the light-emitting layer 106 is described as a green light-emitting layer. However, the red light-emitting layer having the smallest band gap is sandwiched between the green light-emitting layer and the blue light-emitting layer. Is.

  Specifically, in FIGS. 1 and 2, the light emitting layer 104 is a green light emitting layer, the light emitting layer 106 is a red light emitting layer, and the light emitting layer 108 is a blue light emitting layer. The method of forming the light emitting layer is the same as that of the electroluminescence drive display devices 100 and 200.

  When a negative voltage is applied to the cathode 102 and a positive voltage is applied to the anode 111, electrons transported to the light emitting layers 104, 106, and 108 via the electron transport layer 103 and holes transported via the hole transport layer 110 are banded. Red light is emitted as recombination in the red light emitting layer 106 having the smallest gap energy.

  As the voltage is increased, the green light emitting layer 104 and the blue light emitting layer 108 emit light. The blue material has a larger energy band gap than other green and red materials, and therefore, charge injection tends to be poor. (High energy barrier for charge injection) The present invention is characterized in that the blue light emitting layer 108 having a large energy band gap is disposed under the hole transport layer 110 below the anode 111.

  Since it is located under the hole transport layer 110, charge injection does not deteriorate. Further, since the host layers of the green and red light emitting layers formed under the blue light emitting layer are made of the same or similar electron transport layer material as the electron transport layer 103, the electron transport is also efficient.

  Since the green light emitting layer 104 is separated from the anode 111, the hole transport efficiency is poor. However, it is characterized in that the red light emitting layer with the smallest band gap energy is provided above the green layer to improve the hole transport efficiency and improve the light emission balance of red, green and blue.

  Therefore, in FIG. 1, green light 104, red light 106, and blue light 108 are extracted from the substrate 101 side, and the color filter absorbs red, green, and blue using a color filter and a white light emitting layer. Therefore, about three times the brightness can be obtained.

  The same amount of light can be obtained with about a third of the current when a conventional white light emitting layer is used. In addition, by forming the three layers in an overlapping manner, the variation in film thickness is smaller than that in a single-layer electroluminescent element. As a result, the light emission efficiency variation is improved and the current consumption is reduced to 1/3, thereby improving the current variation and the life variation. Since the driving voltage also has three layers overlapping with the white element obtained by emitting blue, green, and red separately, a single voltage is sufficient, and driving is easier and the circuit can be omitted compared to the conventional FIG.

  In addition, since the light is emitted solidly as compared with the white element obtained by individually emitting blue, green, and red in FIG. 3, it is not necessary to take, for example, a light emission width of 0.5 mm and a pitch of 0.5 mm. Can be halved. As a result, the same amount of light emission can be obtained in an area of ½, so that high definition and high luminance can be achieved.

Here, the formal names of the materials described by the above names are as follows.
・ “PBD” ・ ・ 2- (4-biphenylyl) -5- (4-tert-butyphenyl) -1,3,4-oxadiazole ・ “NBP” ・ ・ N, N′-Di ((naphthalene- 1-yl) -N,
N'-diphenyl-benzidine)
・ 「Alq3」 ・ ・ Tris (8-hydroxyquinolinato)
aluminum
"DCJTB" (2) (2- (1,1-Dimethylethyl) -6- (2- (2,3,6,7-tetrahydro-1,1,7,7-tetramethyl-1H, 5H-benzo [ij Quinolizin-9-yl) etheryl) -4H-pyran-4-ylidene) preparedintrile.
"Coumarin 6"-3- (2-Benzothiazolyl) -7- (diethylamino) coumarin.
“BAlq” (1,1′-Bisphenyl-4-Olato) bis (2-methyl-8-quinolinplate-N1,08) Aluminum.
"TPD" (4, 4 ', 4 "-tris (3-methylphenylphenylamino) triphenyline)
"MTDATA" ... (4,4'-bis (3-menthylphenylamino) biphenyl)
In addition, this invention is not limited to the said best form 1,2,3, It is possible to make various deformation | transformation based on the meaning of this invention, and they are excluded from the scope of the present invention. It is not a thing.

  In the present invention, a glass substrate is used as an example, but the present invention can also be applied to a plastic substrate. After the drive display device is formed using the substrate as a thin film metal, it may be bonded to a plastic base material.

  In the present invention, the hole transport layer is used as the transport layer. However, the present invention can be applied to the case where the electron transport layer is used in accordance with the characteristics of the host layer. Furthermore, both a hole transport layer and an electron transport layer may be used.

  In the present invention, a three-layer full-color electroluminescence drive display device has been described. However, as one drive display device unit excluding the electrodes of the substrate 101, the cathode 102, and the anode 111, the drive current becomes 1 / (2-3) n in the case of the same amount of light by stacking n stages. Current consumption and power consumption can be reduced.

  Further, although the present invention has been described with respect to an electroluminescence driving display device using fluorescent light emission, the present invention can also be applied to an electroluminescence driving display device that emits phosphorescence.

  In FIG. 2 of the present invention, the sensor layer 305 is replaced with the gate 205 formed by the mask 2, the sensor layer 313 is replaced by the gate 213 formed by the mask 4, and the sensor layer 314 is replaced by the gate 214 formed by the mask. It can be formed to form an input display using an electroluminescence driven display device.

It is sectional drawing of the electroluminescence drive display apparatus 100 which concerns on the best form 1 for implementing this invention. It is sectional drawing of the electroluminescent drive display apparatus 200 which concerns on the best form 2 for implementing this invention. It is the schematic which shows the basic composition of the conventional electroluminescent element.

Explanation of symbols

100 Electroluminescence Drive Display Device 101 Substrate 102 Cathode (Source Electrode)
103 Electron transport layer 104 Red light emitting layer 105 Transport layer 1
106 Green light emitting layer 107 Transport layer 2
108 Blue light emitting layer 109 Transport layer 3
110 hole transport layer 111 anode (drain electrode)
112 Gate electrode 1
113 Gate electrode 2
114 Gate electrode 3
115 Blue output light 116 Green output light 117 Red output light

Claims (33)

In the electroluminescent light emitting part composed of a plurality of light emitting layers sandwiched between both the cathode and the anode, a transport layer is provided above each light emitting layer, and a gate electrode is formed in each of the transport layers. An electroluminescence driving display device. In an electroluminescent light-emitting portion comprising a plurality of light-emitting layers sandwiched between both cathode and anode electrodes, a transport layer is provided on each light-emitting layer, and a plurality of gate electrodes are staggered in each of the transport layers. An electroluminescence driving display device characterized by being formed into a shape. The light-emitting organic material is provided so that each light-emitting layer has three or more light-emitting layers, and each light-emitting layer is doped with a light-emitting organic material such that the energy band gap value of the light-emitting organic material increases in order from the cathode side. 3. The electroluminescence driving display device according to 2. The light emitting layer is provided with three or more light emitting layers, and each light emitting layer is doped with a light emitting organic material so that the energy band gap value of the light emitting organic material increases in order from the cathode side, and a light emitting layer having the smallest band gap is provided therebetween. The electroluminescence driving display device according to claim 1, wherein the electroluminescence driving display device is sandwiched. The electroluminescent light emitting portion is composed of an electron transport layer, a light emitting layer 1, a transport layer 1, a light emitting layer 2, a transport layer 2, a light emitting layer 3, a transport layer 3, and a hole transport layer between a cathode and an anode. The electroluminescence drive display device according to any one of claims 1 to 4. 6. The electroluminescence driving display device according to claim 1, wherein the light emitting layer 1 is red, the light emitting layer 2 is green, and the light emitting layer 3 is blue. 6. The electroluminescent drive display device according to claim 1, wherein the light emitting layer 1 is green, the light emitting layer 2 is red, and the light emitting layer 3 is blue. 6. The electroluminescence driving display device according to claim 1, wherein the light emitting layer includes “Alq3”. 6. The electroluminescence driving display device according to claim 1, wherein the light emitting layers have different emission spectra. 6. The electroluminescence drive display device according to claim 1, wherein the emission color is blue light, green light, or red light by the combination of the light emitting layers. The electroluminescent drive display device according to claim 1, wherein the emission color is white light by the combination of the light emitting layers. 6. The electroluminescence driving display device according to claim 1, wherein the light quantity of the light emitting layer is adjusted by changing the width of the transport layer sandwiched between the light emitting layers. On the substrate, in the electroluminescence light-emitting part composed of a plurality of light-emitting layers sandwiched between a source electrode and a drain electrode and both electrodes, a transport layer is provided above each light-emitting layer, An electroluminescence driving display device, wherein a gate electrode is formed. In an electroluminescent light emitting section comprising a plurality of light emitting layers sandwiched between a source electrode, a drain electrode and both electrodes on a substrate, each light emitting layer has an energy band gap value of the light emitting organic material from the source electrode side. 14. The electroluminescence driving display device according to claim 13, wherein the light emitting organic material is doped so as to increase in order. In an electroluminescent light emitting section comprising a plurality of light emitting layers sandwiched between a source electrode, a drain electrode and both electrodes on a substrate, each light emitting layer has an energy band gap value of the light emitting organic material from the source electrode side. 15. The electroluminescence driving display device according to claim 13, wherein a light emitting organic material is doped so as to increase in order, and a light emitting layer having the smallest band gap is sandwiched therebetween. The electroluminescent light emitting part is composed of an electron transport layer, a light emitting layer 1, a transport layer 1, a light emitting layer 2, a transport layer 2, a light emitting layer 3, a transport layer 3, and a hole transport layer between a source electrode and a drain electrode. The electroluminescence drive display device according to claim 13, wherein the display device is an electroluminescence drive display device. 17. The electroluminescence drive display device according to claim 13, wherein the light emitting layer 1 is red, the light emitting layer 2 is green, and the light emitting layer 3 is blue. 17. The electroluminescence drive display device according to claim 13, wherein the light emitting layer 1 is green, the light emitting layer 2 is red, and the light emitting layer 3 is blue. The electroluminescent drive display device according to claim 13, wherein the light emitting layer includes “Alq3”. The electroluminescent drive display device according to claim 13, wherein the light emitting layers have emission spectra different from each other. The electroluminescent drive display device according to any one of claims 13 to 20, wherein an emission color is blue light, green light, or red light by a combination of the light emitting layers. The electroluminescent drive display device according to any one of claims 13 to 21, wherein the emission color is white light by the combination of the light emitting layers. The electroluminescence drive display device according to any one of claims 13 to 22, wherein the light amount of the light emitting layer is adjusted by changing a width of the transport layer sandwiched between the light emitting layers. The electroluminescent drive display device according to any one of claims 1 to 23, wherein the cathode or the source electrode is formed of a light transmissive electrode. 25. The electroluminescence table drive indicating device according to claim 1, wherein the anode or drain electrode is formed on the entire surface of the display portion and is formed of a metal electrode. The electroluminescent drive display device according to any one of claims 1 to 25, wherein the anode or drain electrode is formed on the entire surface of the display portion to form a protective layer. In an electroluminescent light emitting portion composed of a plurality of light emitting layers sandwiched between both cathode and anode electrodes, a transport layer is provided above each light emitting layer, and a gate electrode is formed in each transport layer to emit light. The electroluminescence drive display device according to any one of claims 1 to 12, wherein the display device is taken out from a cathode side. On the substrate, in the electroluminescence light-emitting part composed of a plurality of light-emitting layers sandwiched between a source electrode and a drain electrode and both electrodes, a transport layer is provided above each light-emitting layer, 27. The electroluminescence drive display device according to claim 13, wherein a gate electrode is formed and light is extracted from the substrate side. An electroluminescent light emitting unit comprising a source electrode or cathode, a drain electrode or an anode, and a plurality of light emitting layers sandwiched between the electrodes on the substrate, wherein the source electrode or cathode, the drain electrode or anode, An electroluminescence drive display device, wherein the same drive voltage is applied between the two. An electroluminescent light emitting unit comprising a source electrode or cathode, a drain electrode or an anode, and a plurality of light emitting layers sandwiched between the electrodes on the substrate, wherein the source electrode or cathode, the drain electrode or anode, An electroluminescence drive display device, wherein the same drive current is applied between the two. A source electrode or cathode, a drain electrode or anode, a plurality of light emitting layers sandwiched between the electrodes, a step of providing a transport layer on each of the light emitting layers, The method comprises a step of forming a gate electrode in a transport layer, a step of forming the source electrode or the cathode with a light transmissive metal layer, and a step of forming the drain electrode or the anode with a metal layer. Manufacturing method of electroluminescence drive display device. 32. The method of manufacturing an electroluminescence drive display device according to claim 31, wherein the cathode is formed by sputtering and the anode is formed by vapor deposition. 32. The method of manufacturing an electroluminescence driving display device according to claim 31, wherein the source electrode is formed by sputtering and the drain electrode is formed by vapor deposition.

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