JP7591196B2 - display - Google Patents

Description

The present invention relates to a display.

In recent years, organic semiconductor elements have been put to practical use as light source elements, and displays that use organic semiconductor elements as light source elements have become commercially available. Furthermore, in the development of displays that use organic semiconductor elements as light source elements, research is still ongoing to further improve performance, such as by increasing brightness, improving resolution, reducing power consumption, and extending life.

Conventional display pixels that use organic semiconductor elements as light-emitting elements are composed of an organic light-emitting diode (also called "OLED") and a transistor that controls the current flowing through the organic light-emitting diode. An organic light-emitting diode is a device that emits light in response to a current input from a thin-film transistor (also called "TFT") formed on a substrate to an organic EL layer sandwiched between an anode electrode and a cathode electrode.

However, in contrast to this configuration, Patent Document 1 below describes a vertical organic light-emitting transistor (also called a "VOLET") that is a transistor that adjusts the current flowing by controlling the voltage applied to the gate electrode as an element for reducing the number of control elements and increasing the light-emitting area to increase brightness, and that emits light according to the amount of current flowing through the transistor itself. Patent Document 2 below also describes a display that uses a vertical organic light-emitting transistor, and it is expected that the brightness of the display will be significantly increased.

International Publication No. 2009/036071 Special table 2014-505324 publication JP 2018-197864 A

Furthermore, in recent years, displays have been used for a wide variety of purposes, not just for home televisions and personal computers, but also for advertisements in train stations and as backgrounds at event venues. As a result, in addition to improving performance as mentioned above, increasing the size of displays has become a major challenge in the development of displays.

In displays that use organic semiconductors, organic light-emitting diodes and thin-film transistors that form pixels are arranged in the display area, and drivers that drive these are arranged around the outer edge of the display area. This type of configuration is still commonly used in many displays today.

With this configuration, when a display becomes larger, the distance from each driver arranged on the outer edge becomes longer in order to control and drive each element across the entire display area. This results in longer wiring connecting the driver and each element, and the resistance value of the wiring between the driver and the element increases. When the resistance value of the wiring increases, it can cause, for example, a voltage drop due to the flowing current (also known as "IR-Drop"), and signal delays and degradation.

In particular, when this effect becomes significant in the current supply lines that supply current to the light-emitting elements, even if the same voltage is applied from the current supply unit to pass current to each light-emitting element, the voltage drops according to the resistance value of the wiring and the current flowing as the distance from the current supply unit increases. This results in a decrease in the amount of current actually supplied compared to the current value required to display image data. When this effect becomes significant, a display defect occurs in which a person can visually recognize a gradual decrease in brightness. Furthermore, since the current supply lines are often configured to be shared by a group of light-emitting elements arranged in a row, variations in the resistance value of the wiring of the current supply line cause differences in brightness in each line, resulting in line-shaped display defects.

One possible method to address the above issue is to apply to the current supply line a method described in Patent Document 3, in which the light emission brightness of each pixel is detected and a voltage that takes into account the voltage drop is applied to the data line. However, adding complex circuits would significantly compress the light emission area and hinder efforts to increase brightness. Furthermore, the increased number of elements could make breakdowns and malfunctions more likely to occur.

It is also possible to use the outer edge where the driver is located or to add external devices, but making the outer edge larger or adding external devices would limit how the display can be used and where it can be placed, despite the need for a variety of uses.

Furthermore, when applying a voltage value that takes into account fluctuations using control such as feedback, there is a possibility that an error will occur in the calculation method, and there is a good chance that the change in luminance will not be corrected so that it is not visible as a display defect. Therefore, it is more desirable to take measures to prevent display defects as a device structure measure rather than a measure to correct the change in luminance.

Here, the inventors have investigated displays using vertical organic light-emitting transistors and have found that vertical organic light-emitting transistors also have the following problems: Vertical organic light-emitting transistors have a configuration that includes a source electrode, a gate electrode, and a drain electrode, similar to field-effect transistors.

However, unlike field effect transistors such as thin film transistors, vertical organic light emitting transistors have an EL element and an organic semiconductor layer between the source electrode and the drain electrode. Due to the properties of these materials, vertical organic light emitting transistors have the characteristic that the current flowing between the source electrode (anode electrode) and the drain electrode (cathode electrode) is more susceptible to the voltage applied between the electrodes than field effect transistors such as thin film transistors. In other words, the voltage drop in the current supply line is more susceptible than in conventional organic light emitting diode and thin film transistor configurations, and the display defects described above are more likely to occur.

In view of the above problems, the present invention aims to provide a display with improved display quality by improving the device structure to suppress display defects caused by voltage drops in the current supply lines.

The display of the present invention comprises:
A plurality of vertical organic light-emitting transistors arranged in an array in a first direction and a second direction perpendicular to the first direction;
a data line connected to gate electrodes of the vertical organic light emitting transistors and configured to apply a voltage for controlling a current supplied to a source electrode of the vertical organic light emitting transistor;
a thin film transistor connected between a gate electrode of each of the vertical organic light emitting transistors and the data line, for switching between an on state and an off state between the gate electrode of the vertical organic light emitting transistor and the data line;
a gate line connected to a gate electrode of the thin film transistor and applying a voltage for switching the thin film transistor between an on state and an off state;
A plurality of current supply lines are wired in the first direction and supply current to source electrodes of the vertical organic light emitting transistors arranged in the first direction;
and at least one auxiliary line that is wired in the second direction and connects at least two of the current supply lines.

Current supply lines for supplying current to the vertical organic light-emitting transistors are wired in a first direction, shared by a plurality of organic light-emitting transistors arranged in the first direction, and arranged in a plurality of lines in the second direction. At least two of the current supply lines are connected by auxiliary lines wired in the second direction.

There can be any number of auxiliary lines formed, as long as they connect two or more current supply lines. In addition, it is preferable that the current supply lines connected by the auxiliary lines connect current supply lines that are arranged nearby, but it is not necessary that they connect adjacent current supply lines.

By using the above configuration, even if a large localized voltage drop occurs in one current supply line, the voltage of the other current supply lines connected by the auxiliary line is applied, and the voltages of the current supply lines are equalized to suppress the localized voltage drop. This makes it difficult to see pixel areas or lines that are extremely low in brightness compared to the surrounding pixels, greatly improving display quality.

Furthermore, in the above configuration, the auxiliary lines connect the current supply lines in the second direction, so that a voltage drop occurs across the entire screen, rather than a voltage drop for each current supply line, and a gradation-like drop in brightness occurs. Therefore, even in a configuration in which a voltage is applied that takes the voltage drop into account as described above, the voltage can be adjusted two-dimensionally and collectively in response to the brightness trend of the entire screen, such as a gradation-like correction process, rather than correcting for each current supply line. Therefore, brightness correction through complex calculations for each current supply line 12 is no longer necessary, and even if an error occurs in the calculation method, correction is performed across the entire screen, so no local display defects occur and are less likely to be visually recognized as display defects.

In the above display,
The auxiliary line may be formed closer to the substrate than the source electrode of the vertical organic light-emitting transistor.

The pixel configuration of a display using organic light-emitting diodes is minimal, with two thin-film transistors formed in the lower layer, with the upper layer facing away from the substrate, and an organic light-emitting diode formed in the upper layer. In contrast, the pixel configuration of a display using vertical organic light-emitting transistors is minimal, with one thin-film transistor formed in the lower layer, and a vertical organic light-emitting transistor formed in the upper layer. This means that the area of one thin-film transistor that is no longer needed in the lower layer can be utilized. If this area is used as a wiring area, it is possible to maintain or improve the brightness compared to conventional pixel configurations, and also to form an auxiliary line.

In the above display,
At least a part of the auxiliary line may be made of the same material as the gate line and may be formed in the same layer as the gate line.

The gate electrode of a thin-film transistor is formed in a lower layer relative to the source electrode and drain electrode of the thin-film transistor. For this reason, in many cases, the gate line connected to the gate electrode of the thin-film transistor is wired in the bottom layer closest to the substrate, and the data lines and power lines connected to light-emitting devices such as organic light-emitting diodes and vertical organic light-emitting transistors are wired in a layer above the gate line so that they can be easily connected to the light-emitting devices. In other words, the layer on which the gate line is wired is easier to use for wiring than other layers.

In addition, displays using vertical organic light-emitting transistors have one less thin-film transistor than displays using organic light-emitting diodes, so the area where the thin-film transistor is no longer needed can be utilized, minimizing the reduction in the light-emitting area and allowing auxiliary lines to be formed without significantly reducing brightness.

In addition, the material that constitutes the gate line is wiring for applying voltage to control the thin-film transistor at high speed, and is made of a material with a lower resistance value compared to the materials of the other layers. Therefore, by making the auxiliary line out of the same material as the gate line, the influence of the resistance value of the auxiliary line between the current supply lines connected by the auxiliary line can be reduced, and the voltage between the current supply lines can be made more uniform.

In the above display,
At least a part of the auxiliary line may be made of the same material as that constituting the gate electrode of the vertical organic light-emitting transistor, and may be formed in the same layer as the gate electrode of the vertical organic light-emitting transistor.

The above configuration makes it possible to form auxiliary lines even in cases where it is necessary to configure a complex control circuit below the vertical organic light-emitting transistor and it is difficult to secure wiring space. In addition, the auxiliary lines can be formed in parallel with the auxiliary lines formed in the same layer as the above-mentioned gate lines, running in parallel above the auxiliary lines, making it possible to more uniform the voltages between the current supply lines.

The display of the present invention comprises:
A plurality of vertical organic light-emitting transistors arranged in an array in a first direction and a second direction perpendicular to the first direction;
a data line connected to gate electrodes of the vertical organic light emitting transistors and configured to apply a voltage for controlling a current supplied to a source electrode of the vertical organic light emitting transistor;
a thin film transistor connected between a gate electrode of each of the vertical organic light emitting transistors and the data line, for switching between an on state and an off state between the gate electrode of the vertical organic light emitting transistor and the data line;
a gate line connected to a gate electrode of the thin film transistor and applying a voltage for switching the thin film transistor between an on state and an off state;
Among the plurality of vertical organic light emitting transistors, at least two adjacent vertical organic light emitting transistors have source electrodes integrally formed.

With the above configuration, the source electrode of the vertical organic light-emitting transistor is directly connected to the source electrode of the adjacent vertical organic light-emitting transistor, so there is no significant difference in the voltage value applied to the source electrode of each vertical organic light-emitting transistor.

Furthermore, with the above configuration, the source electrode of the vertical organic light-emitting transistor can be formed over a large area, eliminating the need for highly accurate patterning. Therefore, the source electrode of the vertical organic light-emitting transistor can be formed by simpler patterning, such as inkjet screen printing, which is a printing method. This makes it possible to suppress the increase in manufacturing steps and process costs due to the formation and patterning of the source electrode of the vertical organic light-emitting transistor.

Furthermore, by connecting the source electrodes of the vertical organic light-emitting transistors, current can be shared between the connected pixels and the surrounding pixels, eliminating the need to form some contact holes. This simplifies the method of forming the contact holes, preventing increases in process costs and preventing a decrease in panel manufacturing yield due to contact defects.

In the above display,
The vertical organic light emitting transistor may further include a plurality of current supply lines that are wired in the first direction and supply current to source electrodes of the vertical organic light emitting transistors that are arranged in the first direction.

In the above display, the source electrode is integrally formed between multiple vertical organic light-emitting transistors, so the current supplied to the vertical organic light-emitting transistors is supplied via the source electrode. However, by configuring the current supply lines together, the resistance between the source electrodes of each vertical organic light-emitting transistor is reduced, and the voltage of the source electrodes of each vertical organic light-emitting transistor is made more uniform.

In the above display,
At least one auxiliary line may be provided that is wired in the second direction and connects at least two of the current supply lines.

In the above display,
The auxiliary line may be formed closer to the substrate than the source electrode of the vertical organic light-emitting transistor.

In the above display,
At least a part of the auxiliary line may be made of the same material as the gate line and may be formed in the same layer as the gate line.

In the above display,
At least a part of the auxiliary line may be made of the same material as that constituting the gate electrode of the vertical organic light-emitting transistor, and may be formed in the same layer as the gate electrode of the vertical organic light-emitting transistor.

According to each of the above configurations, the resistance between the source electrodes of each vertical organic light-emitting transistor is reduced, and the voltage of the source electrodes of the vertical organic light-emitting transistor is made more uniform.

According to the present invention, by improving the device structure, display defects caused by voltage drops in the current supply lines are suppressed, resulting in a display with improved display quality.

FIG. 2 is a schematic diagram of a portion of an embodiment of a display. FIG. 2 is a circuit diagram of a light-emitting portion in the area A1 of the display of FIG. 1. FIG. 2 is a top view showing a schematic element configuration of a light-emitting portion and its periphery according to an embodiment of the present invention. This is a cross-sectional view taken along line AA' of FIG. This is a cross-sectional view taken along the line BB' of Figure 3. FIG. 2 is a top view showing a schematic element configuration of a light-emitting portion and its periphery according to an embodiment of the present invention. This is a cross-sectional view taken along line AA' of Figure 6. This is a cross-sectional view taken along the line BB' of Figure 6. FIG. 2 is a top view showing a schematic element configuration of a light-emitting portion and its periphery according to an embodiment of the present invention. This is a cross-sectional view taken along line AA' of Figure 9.

The configuration of the display of the present invention will be described below with reference to the drawings. Note that the drawings are all schematic illustrations, and the dimensional ratios and numbers in the drawings do not necessarily match the actual dimensional ratios and numbers.

[First embodiment]
Fig. 1 is a schematic diagram of a portion of an embodiment of a display 1. As shown in Fig. 1, the display 1 of this embodiment includes a light-emitting section 10 including vertical organic light-emitting transistors arranged in an array, a data line 11 for applying a voltage to a gate electrode of the vertical organic light-emitting transistor, a current supply line 12 for supplying a current to a source electrode of the vertical organic light-emitting transistor, a gate line 13 for applying a voltage to control the thin-film transistor, and an auxiliary line 14 for connecting the current supply line 12.

The display 1 also includes, at its outer edge, a source driver 15a that applies a voltage to the data line 11 corresponding to image data to be displayed on the gate electrode of the vertical organic light-emitting transistor, a current supply unit 15b that supplies current to the current supply line 12 and supplies current to the source electrode of the vertical organic light-emitting transistor, and a gate driver 15c that outputs a control signal for the thin-film transistor to the gate line 13.

2 is a detailed circuit diagram of the light-emitting unit 10 in the area A1 of the display 1 in FIG. 1. As shown in FIG. 2, the light-emitting unit 10 includes a vertical organic light-emitting transistor 20, a thin-film transistor 21 that controls the voltage applied to the gate electrode of the vertical organic light-emitting transistor 20, and a capacitor 23 connected between the source electrode and gate electrode of the vertical organic light-emitting transistor 20. In the explanation of FIG. 1 and FIG. 2, the direction in which the current supply line 12 is wired is the X direction (first direction), and the direction in which the auxiliary line 14 is wired is the Y direction (second direction).

The data line 11 is a wiring that applies a voltage output from the source driver 15a to the gate electrode of the vertical organic light-emitting transistor 20 via the thin film transistor 21 in order to adjust the light emission brightness of the vertical organic light-emitting transistor 20 according to the image to be displayed. In this embodiment, the data line 11 is formed in the X direction, but it may be formed in the Y direction.

The current supply line 12 is formed to be connected to a plurality of vertical organic light-emitting transistors 20 arranged in the X direction. Each current supply line 12 supplies a current output from the current supply unit 15b to the source electrodes of the plurality of vertical organic light-emitting transistors 20 arranged in the X direction.

The gate line 13 is connected to the gate electrode of the thin film transistor 21, and applies a control voltage output from the gate driver 15c to the gate electrode of the thin film transistor 21 to switch the thin film transistor 21 between an on state and an off state, thereby controlling the flow of electricity between the gate electrode of the vertical organic light-emitting transistor 20 and the data line 11. In this embodiment, the gate line 13 is formed in the Y direction, but it may be formed in the X direction.

The auxiliary lines 14 are wired in the Y direction between the light-emitting units 10 arranged in the X direction. Note that the auxiliary lines 14 do not have to be formed between all of the light-emitting units 10 arranged in the X direction. In this embodiment, the current supply lines 12 are formed in the X direction and the auxiliary lines 14 in the Y direction, but the current supply lines 12 may be formed in the Y direction and the auxiliary lines 14 in the X direction.

The capacitor 23 is a voltage holding element between the gate electrode and source electrode of the vertical organic light-emitting transistor 20, which is arranged to maintain the displayed image for a predetermined period of time while the thin-film transistor 21 is in the off state.

Next, the structure of each element formed on the substrate will be described. FIG. 3 is a top view of a schematic element configuration of an embodiment of the light-emitting section 10 and its surroundings. FIG. 4 is a cross-sectional view taken along line A-A' in FIG. 3. As shown in FIGS. 3 and 4, the vertical organic light-emitting transistor 20 and thin-film transistor 21 are formed in areas partitioned by the data line 11, current supply line 12, and gate line 13.

Figure 5 is a cross-sectional view taken along line B-B' in Figure 3. As shown in Figures 3 and 5, the auxiliary line 14 is formed from the same material as the gate line 13 in the same layer as the gate line 13 connected to the gate electrode layer 21g of the thin-film transistor 21. Hereinafter, the auxiliary line 14, which is in the same layer as the gate line 13 and is made of the same material, will be described as the wiring layer auxiliary line 14a, but the auxiliary line 14 may be formed in a different layer from the gate line 13 and made of a different material from the gate line 13.

The substrate 30 is transparent to light and transmits the light emitted from the vertical organic light-emitting transistor 20 to the outside. Specific materials will be described later.

In the following explanation, the direction in which the data lines 11 and current supply lines 12 are wired is the X direction, the direction in which the gate lines 13 are wired is the Y direction, the direction perpendicular to these is the Z direction, and the direction away from the substrate 30 (+Z direction) is the upper layer side.

The vertical organic light-emitting transistor 20 is configured such that, from the top, a drain electrode layer 20d corresponding to a cathode electrode, an organic EL layer 20c, an organic semiconductor layer 20a, a source electrode layer 20s configured to coat the surface of the surface layer 31 with a conductive material containing carbon (carbon nanotubes in this embodiment), and a gate electrode layer 20g formed below through a gate insulating film layer 20h composed of a dielectric. When a voltage is applied to the gate electrode layer 20g, the Schottky barrier between the organic semiconductor layer 20a and the source electrode layer 20s changes, and when the voltage exceeds a predetermined threshold, a current flows from the source electrode layer 20s to the organic semiconductor layer 20a and the organic EL layer 20c, causing the vertical organic light-emitting transistor 20 to emit light.

In the display 1 of this embodiment, the substrate 30 is made of a material that is transparent to visible light, and the gate electrode layer 20g and the source electrode layer 20s are configured to have a gap that allows visible light to pass through, so that light emitted from the organic EL layer 20c passes through the substrate 30 and is emitted to the outside, thereby displaying an image. This method of emitting light through the substrate 30 is also called the "bottom emission method," and has the advantage of being easy to manufacture and easy to connect the wiring between electrodes.

In the thin-film transistor 21, the source electrode layer 21s and the drain electrode layer 21d are connected via the oxide semiconductor layer 21a, and the gate electrode layer 21g is formed below the oxide semiconductor layer 21a via an insulating film layer or a dielectric layer. When a voltage is applied to the gate electrode layer 21g, a channel is formed in the oxide semiconductor layer 21a, and the source electrode layer 21s and the drain electrode layer 21d are electrically connected.

The thin-film transistor 21 has a source electrode layer 21s connected to the data line 11 and a drain electrode layer 21d connected to the gate electrode layer 20g of the vertical organic light-emitting transistor 20.

As shown in FIG. 3, in order to achieve high brightness, the vertical organic light-emitting transistor 20 is formed so as to fill almost the entire area partitioned by the data line 11, the current supply line 12, and the gate line 13, and the thin-film transistor 21 is formed as small as possible in the corner of the partitioned area so as to have little effect on the light-emitting area of the vertical organic light-emitting transistor 20.

In the first embodiment, as shown in FIG. 3 and FIG. 5, the auxiliary line 14 is formed on the −Z side of the source electrode layer 20s of the vertical organic light-emitting transistor 20, that is, on the substrate 30 side, but it may be formed on the +Z side of the source electrode layer 20s.

Although the capacitor 23 is not shown in Figures 3 to 5, as shown in Figure 3, the vertical organic light-emitting transistor 20 of this embodiment is provided with a capacitor 23 as a parasitic element by arranging the source electrode layer 20s and the gate electrode layer 20g so that they face each other via the gate insulating film layer 20h, and the capacitor 23 can also function to maintain voltage. If the capacitance value of such a parasitic element capacitor 23 is insufficient, an additional capacitor may be formed.

The following are examples of materials that can be used for each layer:

The gate line 13 and the wiring layer auxiliary line 14a may be made of aluminum (Al), titanium (Ti), molybdenum (Mo), tungsten (W), niobium (Nb), magnesium (Mg), silver (Ag), copper (Cu), or alloys of combinations thereof.

The substrate 30 may be made of glass or a plastic material such as PET (Poly Ethylene Terephthalate), PEN (Poly Ethylene Naphthalate), or polyimide.

The drain electrode layer 20d of the vertical organic light-emitting transistor 20 may be made of single-layer or multi-layer graphene, carbon nanotubes, aluminum (Al), lithium fluoride (LiF), molybdenum oxide (Mo _x O _y ), indium tin oxide (ITO), zinc oxide (ZnO), and the like.

The gate electrode layer 20g of the vertical organic light-emitting transistor 20 may employ materials including zinc oxide (ZnO) doped with metals such as aluminum (Al), tin (Sn), yttrium (Y), scandium (Sc), gallium ( _Ga ), etc., indium oxide ( _In2O3 ), tin dioxide ( _SnO2 ), metal-doped or undoped transparent conductive oxides such as cadmium oxide (CdO), and combinations thereof, or aluminum (Al), gold (Au), silver (Ag), platinum (Pt), cadmium (Cd), nickel (Ni), and tantalum (Ta), and combinations thereof, as well as p- or n-doped silicon (Si), gallium arsenide (GaAs), etc.

The gate insulating film layer 20h between the surface layer 31 of the vertical organic light-emitting transistor 20 and the gate electrode layer 20g may be made of silicon oxide ( _SiOx ), aluminum oxide ( _{Al2O3 )} , silicon nitride ( _Si3N4 ), _yttrium oxide ( _Y2O3 ), lead titanate ( _PbTiOx ), aluminum titanate ( _AlTiOx ), glass _, and organic compounds such as parylene polymer, polystyrene, polyimide, polyvinylphenol, polymethyl methacrylate, and fluoropolymer.

The organic semiconductor layer 20a of the vertical organic light-emitting transistor 20 is made of a linear condensed polycyclic aromatic compound (or acene compound) such as naphthalene, anthracene, rubrene, tetracene, pentacene, hexacene, and derivatives thereof, a pigment such as, for example, a copper phthalocyanine (CuPc)-based compound, an azo compound, a perylene-based compound, and derivatives thereof, and a pigment such as, for example, a hydrazone compound, a triphenylmethane-based compound, a diphenylmethane-based compound, a stilbene-based compound, an allylvinyl compound, a pyrazoline-based compound, a triphenylamine derivative (TPD), an allylamine compound, a low molecular weight amine derivative (a-NPD), 2,2',7,7'-tetrakis(diphenylamino)-9,9'-spirobifluorene (spiro- low molecular weight compounds such as N,N'-di(1-naphthyl)-N,N'-diphenyl-4,4'-diamonobiphenyl (spiro-NPB), 4,4',4"-tris[N-3-methylphenyl-N-phenylamino]triphenylamine (mMTDATA), 2,2',7,7'-tetrakis(2,2-diphenylvinyl)-9,9-spirobifluorene (spiro-DPVBi), 4,4'-bis(2,2-diphenylvinyl)biphenyl (DPVBi), (8-quinolinolato)aluminum (Alq), tris(8-quinolinolato)aluminum (Alq3), tris(4-methyl-8-quinolinolato)aluminum (Almq3), and derivatives thereof; and polythiophenes, poly(p polymer compounds such as poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (PPV), biphenyl group-containing polymers, dialkoxy group-containing polymers, alkoxyphenyl PPV, phenyl PPV, phenyl/dialkoxy PPV copolymers, poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV), poly(ethylenedioxythiophene) (PEDOT), poly(styrenesulfonic acid) (PSS), poly(aniline) (PAM), poly(N-vinylcarbazole), poly(N-vinylcarbazole), poly(vinylpyrene), poly(vinylanthracene), pyrene formaldehyde resins, ethylcarbazole formaldehyde halogenated resins, and modified products thereof; For example, 5,5_-diperfluorohexylcarbonyl-2,2_:5_,2_:5_,2_-quaterthiophene (DFHCO-4T), DFH-4T, DFCO-4T, P(NDI2OD-T2), PDI8-CN2, PDIF-CN2, F16CuPc, and n-type transport organic small molecules, oligomers, or polymers such as fullerene, naphthalene, perylene, and oligothiophene derivatives, as well as aromatic compounds having a thiophene ring such as thieno[3,2-b]thiophene, dinaphthyl[2,3-b:2',3'-f]thieno[3,2-b]thiophene (DNTT), and 2-decyl-7-phenyl[1]benzothieno[3,2-b][1]benzothiophene (BTBT), may be employed.

Here, the vertical organic light-emitting transistor 20 can be suitably used with a hole injection layer, hole transport layer, organic EL layer, electron transport layer, electron injection layer, etc., which are standardly used in OLED displays, by appropriately selecting an organic semiconductor with a suitable energy level. The color of the light emitted to the outside can be adjusted to emit light of a color such as red, green, or blue by selecting the material that constitutes the organic EL layer 20c described above. The vertical organic light-emitting transistor 20 can also be configured to emit white light, or the same vertical organic light-emitting transistor 20 can be used to select and emit light of a desired color using a color filter.

The surface layer 31 is a layer formed on the gate insulating film layer 20h for the purpose of adhering the source electrode layer 20s (particularly the CNT layer). The surface layer 31 can be formed by applying a composition containing a binder resin formed from a silane coupling material, an acrylic resin, or the like.

The oxide semiconductor layer 21a formed in the thin film transistor 21 may be an In-Ga-Zn-O based semiconductor, a Zn-O based semiconductor (ZnO), an In-Zn-O based semiconductor (IZO (registered trademark)), a Zn-Ti-O based semiconductor (ZTO), a Cd-Ge-O based semiconductor, a Cd-Pb-O based semiconductor, CdO (cadmium oxide), an Mg-Zn-O based semiconductor, an In-Sn-Zn-O based semiconductor (e.g., _In2O3 - _SnO2 - _ZnO ), an In-Ga-Sn-O based semiconductor, or the like.

In this embodiment, the thin-film transistor 21 is a thin-film transistor made of an oxide semiconductor, but it may be a thin-film transistor made of amorphous silicon. It may be either a p-type or an n-type. Furthermore, as a specific configuration, any of the following configurations may be adopted: a staggered type, an inverted staggered type, a coplanar type, an inverted coplanar type, etc.

Between the organic semiconductor layer 20a and the surface layer 31, a bank layer 24 is formed for insulation, and where the source electrode layer 20s is connected to the data line 11, the bank layer 24 is filled to fill the gap formed between the surface layer 31 and the gate insulating film layer 20h for connection.

As the vertical organic light-emitting transistor 20, the vertical organic light-emitting transistor 20 described in the above Patent Documents 1 and 2 can also be used, and furthermore, the configuration of the above Patent Document 3 can also be used.

With the above configuration, the current supply lines 12 are connected by the wiring layer auxiliary lines 14a, and at the connection points with the wiring layer auxiliary lines 14a, the voltage value of the connection points of the other current supply lines 12 connected thereto is shared. In other words, even if an extreme voltage drop occurs in one area due to variations in the resistance values of the current supply lines 12, the voltage is raised by the other current supply lines 12 connected to the wiring layer auxiliary lines 14a. And, as in this embodiment, the more connections there are between the current supply lines 12 and the wiring layer auxiliary lines 14a, the more uniform the voltage of the current supply lines 12 will be throughout the entire display 1.

In this way, the voltage of the current supply lines 12 connected by the wiring layer auxiliary lines 14a is equalized. Therefore, a display 1 with improved display quality is realized in which local voltage drops are unlikely to occur in each current supply line 12 and display defects are unlikely to be visually recognized.

[Second embodiment]

The configuration of the second embodiment of the display 1 of the present invention will be described below, focusing on the differences from the first embodiment.

Figure 6 is a top view of a schematic element configuration of the light-emitting section 10 and its periphery in one embodiment. Figure 7 is a cross-sectional view taken along the line A-A' in Figure 6. Figure 7, which is a cross-sectional view taken along the line A-A' in Figure 6, has the same configuration as Figure 4, which is the first embodiment. Figure 8 is a cross-sectional view taken along the line B-B' in Figure 6. As shown in Figures 6 and 8, in the second embodiment, in addition to the wiring layer auxiliary line 14a, an electrode layer auxiliary line 14b made of the same material as the gate electrode layer 20g is arranged in parallel in the same layer as the gate electrode layer 20g of the vertical organic light-emitting transistor 20.

As described above, the electrode layer auxiliary line 14b is formed in the same layer as the gate electrode layer 20g of the vertical organic light-emitting transistor 20, and therefore cannot be formed in the region where the vertical organic light-emitting transistor 20 is formed. Therefore, it is formed in a region different from the vertical organic light-emitting transistor 20. However, since the wiring layer auxiliary line 14a and the electrode layer auxiliary line 14b are formed in different layers, they can be formed to overlap in the Z direction, as shown in Figures 6 and 8.

In other words, the above configuration makes it possible to reduce the resistance value of each auxiliary line 14 (14a, 14b) while minimizing the reduction in the light-emitting area. The lower the resistance value of the auxiliary line 14 (14a, 14b), the smaller the voltage drop due to the current flowing through the auxiliary line 14 (14a, 14b), and therefore the voltage difference in each current supply line 12 can be reduced. Therefore, local voltage drops are less likely to occur in each current supply line 12, and a display 1 with improved display quality is realized.

[Third embodiment]
The configuration of the third embodiment of the display 1 of the present invention will be described, focusing on the differences from the first and second embodiments.

In the above explanation, a configuration in which only the wiring layer auxiliary line 14a is formed and a configuration in which both the wiring layer auxiliary line 14a and the electrode layer auxiliary line 14b are formed are described, but it is also acceptable for only the electrode layer auxiliary line 14b to be formed.

[Fourth embodiment]
The configuration of the fourth embodiment of the display 1 of the present invention will be described, focusing on the differences from the first, second and third embodiments.

Figure 9 is a top view of a schematic element configuration of an embodiment of the light-emitting section 10 and its surroundings. Figure 10 is a cross-sectional view taken along the line A-A' in Figure 9. As shown in Figures 9 and 10, in the fourth embodiment, the source electrode layer 20s of the vertical organic light-emitting transistor 20 is integrally formed between at least two or more pixels, and is configured to essentially function as a current supply line 12.

And, as in the fourth embodiment, the more pixels in which the source electrode layers 20s are connected to each other, the more uniform the voltage of the source electrode layers 20s of each vertical organic light-emitting transistor 20 is across the display 1, and display defects are less likely to be visually recognized, resulting in a display 1 with improved display quality.

In the fourth embodiment, the source electrode layer 20s of each vertical organic light-emitting transistor 20 is integrally formed, and the current supply line 12 is not formed, but it may be formed together with the configuration of the fourth embodiment.

[Fifth embodiment]
The configuration of the fifth embodiment of the display 1 of the present invention will be described, focusing on the differences from the first to fourth embodiments.

The fourth embodiment in which the current supply line 12 is formed and the structures of the first to third embodiments make it possible to form at least one auxiliary line that connects at least two current supply lines 12. These measures make it possible to reduce the voltage difference in each current supply line 12 compared to the fourth embodiment. As a result, local voltage drops are less likely to occur in each current supply line 12, and a display 1 with improved display quality is realized.

The auxiliary line may be formed closer to the substrate 30 than the source electrode layer 20s of the vertical organic light-emitting transistor 20.

In addition, at least a portion of the auxiliary line may be made of the same material as the gate line 13, and at least a portion of the auxiliary line may be formed in the same layer as the gate line 13.

Furthermore, at least a portion of the auxiliary line may be made of the same material as the material constituting the gate electrode layer 20g of the vertical organic light-emitting transistor 20, and may be formed in the same layer as the gate electrode layer 20g of the vertical organic light-emitting transistor 20.

[Another embodiment]
Another embodiment will be described below.

<1> The display 1 may be configured to display an image by emitting light emitted from the organic EL layer 20c to the opposite side of the substrate 30. This configuration is also called a "top emission type" and has the advantage that elements and wiring can be configured even between the vertical organic light-emitting transistor 20 and the substrate 30.
<2> The configurations and control methods of the display 1 described above are merely examples, and the present invention is not limited to the configurations shown in the drawings.

1: Display 10: Light-emitting section 11: Data line 12: Current supply line 13: Gate line 14, 14a, 14b: Auxiliary line 15a: Source driver 15b: Current supply section 15c: Gate driver 20: Vertical organic light-emitting transistor 20a: Organic semiconductor layer 20c: Organic EL layer 20d: Drain electrode layer 20g: Gate electrode layer 20h: Gate insulating film layer 20s: Source electrode layer 21: Thin film transistor 21a: Oxide semiconductor layer 21d: Drain electrode layer 21g: Gate electrode layer 21s: Source electrode layer 23: Capacitor 24: Bank layer 30: Substrate 31: Surface layer

Claims (6)

A plurality of vertical organic light-emitting transistors arranged in an array in a first direction and a second direction perpendicular to the first direction;
a data line connected to gate electrodes of the vertical organic light emitting transistors and configured to apply a voltage for controlling a current supplied to a source electrode of the vertical organic light emitting transistor;
a thin film transistor connected between a gate electrode of each of the vertical organic light emitting transistors and the data line, for switching between an on state and an off state between the gate electrode of the vertical organic light emitting transistor and the data line;
a gate line connected to a gate electrode of the thin film transistor and applying a voltage for switching the thin film transistor between an on state and an off state;
A display, characterized in that source electrodes of at least two adjacent vertical organic light-emitting transistors among the plurality of vertical organic light-emitting transistors are integrally formed. The display according to claim 1 , further comprising a plurality of current supply lines wired in the first direction and supplying current to source electrodes of a plurality of the vertical organic light-emitting transistors arranged in the first direction. The display according to claim 2 , further comprising at least one auxiliary line wired in the second direction and connecting at least two of the current supply lines. 4. The display according to claim 3 , wherein the auxiliary line is formed closer to the substrate than the source electrode of the vertical organic light-emitting transistor. 5. The display according to claim 3 , wherein at least a part of the auxiliary line is made of the same material as the gate line and is formed in the same layer as the gate line. A display according to any one of claims 3 to 5, characterized in that at least a part of the auxiliary line is made of the same material as the material constituting the gate electrode of the vertical organic light-emitting transistor and is formed in the same layer as the gate electrode of the vertical organic light-emitting transistor.