TW201724494A - Organic light-emitting diode display device - Google Patents

Abstract

An organic light-emitting diode display device includes a substrate on which red, green and blue sub-pixel regions are defined; first electrodes in the red, green and blue sub-pixel regions, respectively; first, second and third light-emitting layers on the first electrodes and in the red, green and blue sub-pixel regions, respectively; a second electrode on the first, second and third light-emitting layers; and red, green and blue color filters on the second electrode and corresponding to the red, green and blue sub-pixel regions, respectively, wherein a thickness of the first light-emitting layer is smaller than a thickness of the second light emitting layer.

Description

Organic light emitting diode display device

The present invention relates to an organic light emitting diode display device, and more particularly to an organic light emitting diode display device capable of improving life.

Recently, flat panel displays have been extensively developed and implemented in various fields due to their thin and light appearance, low weight, and low power consumption of flat panel displays.

In a flat panel display, an Organic Light-Emitting Diode (OLED) display device, which may be referred to as an organic electroluminescence display device, emits light in the loss of an electron hole pair. The electron hole pair is formed by injecting a charge into a light-emitting layer between a cathode for injecting electrons and an anode for injecting a hole.

The OLED display device can include a flexible substrate, such as plastic. Since the OLED display device is self-illuminating, it has excellent contrast. OLED display devices have a reaction time of a few microseconds and have an advantage in displaying moving images. The OLED display device has a large viewing angle.

According to the driving method, the OLED display device can be classified into a passive matrix OLED display device and an active matrix OLED display device. Active matrix OLED display devices have low power consumption and high image quality. In addition, the size of the active matrix OLED display device can be large.

An OLED display device includes a plurality of pixels to represent various colors. Each pixel includes red, green, blue sub-pixels, and red, green, and blue organic light-emitting diodes The polar bodies are formed in red, green, and blue sub-pixels, respectively.

The red, green, and blue organic light emitting diodes respectively include red, green, and blue light emitting material layers, and each of the light emitting material layers is formed by a thermal evaporation method. In detail, the luminescent material layer is formed by selectively evaporating an organic luminescent material using a precision metal mask. However, it is difficult to implement the thermal evaporation method to a display device having a large size and a high image quality because of variations in shading, depression, and masking.

In order to solve this problem, a method of forming the luminescent material layer by a solution procedure has been proposed. In the solution program, a bank layer is formed around a pixel region, and a luminescent material is dropped into the cell surrounded by the bank layer by scanning a nozzle of an injection device in a specific direction. In the pixel region, and the dropped luminescent material is hardened to thereby form the luminescent material layer. At this time, a hole injection layer and a hole transport layer can also be formed by the solution process.

Moreover, the red, green, and blue luminescent materials have different characteristics. In particular, the red luminescent material has a relatively low efficiency and the green luminescent material has a relatively low lifetime. Therefore, it is not simple to ensure a red, green, and blue luminescent material having a consistent lifetime and efficiency, and the life of the OLED display device may be lowered.

Meanwhile, in the OLED display device, the reflection of the external light source is high. The reflection of the external source will increase the brightness in the black state and the contrast will decrease. Therefore, the image quality is degraded due to the reflection of the external light source. In order to prevent reflection from an external light source, a polarizer is used, which causes an increase in cost.

Accordingly, the present invention is directed to an OLED display device that can largely obviate one or more problems due to limitations or disadvantages of the prior art.

It is an object of the present invention to provide an OLED display device with increased lifetime.

Another object of the present invention is to provide an OLED display device with reduced cost.

Other features and advantages of the invention will be set forth in the description which follows. The object and other advantages of the present invention are It is achieved and achieved by the attached embodiments, the scope of the patent application, and the structure of the drawings.

In order to achieve the above and other advantages in accordance with the purpose of the present invention, as embodied and described below, an organic light emitting diode display device includes: a substrate having a red sub-pixel region, a green sub-pixel region, and a blue sub-pixel region; a plurality of first electrodes respectively in the red sub-pixel region, the green sub-pixel region, and the blue sub-pixel region; a first luminescent layer, a second luminescent layer, and a a third illuminating layer, the illuminating layers are located on the first electrodes and in the red sub-pixel region, the green sub-pixel region, and the blue sub-pixel region, respectively; a second electrode is located at the first illuminating layer a layer, the second luminescent layer, and the third luminescent layer; and a red color filter layer, a green color filter layer, and a blue color filter layer, wherein the color filter layers are located at the second And corresponding to the red sub-pixel region, the green sub-pixel region, and the blue sub-pixel region, wherein the thickness of the first luminescent layer is smaller than the second The thickness of the optical layer.

It is to be understood that the foregoing general description

110‧‧‧Substrate

122‧‧‧Semiconductor layer

130‧‧‧gate insulation

132‧‧‧gate electrode

140‧‧‧Inter-insulation

140a‧‧‧first contact hole

140b‧‧‧second contact hole

142‧‧‧Source electrode

144‧‧‧汲electrode

152‧‧‧First passivation layer

154‧‧‧second passivation layer

156‧‧‧汲polar contact hole

162‧‧‧first electrode

170‧‧‧deck layer

180‧‧‧Lighting layer

182‧‧‧ hole auxiliary layer

184‧‧‧ luminescent material layer

186‧‧‧Electronic auxiliary layer

192‧‧‧second electrode

200‧‧‧ coating

210‧‧‧relative substrate

220‧‧‧Color filter layer

B‧‧‧Deep blue light

Bc‧‧‧Blue color filter layer

Cst‧‧‧ storage capacitor

De‧‧‧Organic Luminescent Diode

DL‧‧‧ data line

G‧‧‧Dark green light

Gc‧‧‧Green color filter

GL‧‧‧ gate line

Gy‧‧‧ yellowish green light

P‧‧‧pixel area

Pb‧‧‧ blue sub-pixel area

Pg‧‧‧Green sub-pixel area

Pr‧‧‧Red sub-pixel area

R‧‧‧Deep red light

Rc‧‧‧Red color filter

Ry‧‧‧ yellowish red light

Td‧‧‧Drive film transistor

Ts‧‧‧ Switching Film Transistor

VDD‧‧‧High voltage supply terminal

VSS‧‧‧ low voltage supply

The drawings are included to provide a further understanding of the embodiments of the invention, In the drawings: FIG. 1 is a circuit diagram of a pixel region of an OLED display device according to an embodiment of the invention; FIG. 2 is a cross-sectional view of the OLED display device according to the embodiment of the present invention; A schematic diagram of red, green, and blue sub-pixels of an OLED display device according to the embodiment of the present invention; FIG. 4 is a schematic cross-sectional view showing light output from the OLED display device according to the embodiment of the present invention; FIG. 5A is a display basis A diagram of a spectrum of light emitted from a red and green sub-pixel region of an organic light-emitting diode of an OLED display device according to this embodiment of the present invention, and FIG. 5B is a diagram A diagram showing a spectrum of light outputted from a red and green sub-pixel region of an OLED display device according to the embodiment of the present invention; and FIG. 6A is a diagram showing a CIE x color coordinate according to a thickness of the hole auxiliary layer, 6B is a diagram showing the CIE y color coordinates according to the thickness of the hole auxiliary layer, and FIG. 6C is a diagram showing the current efficiency according to the thickness of the hole auxiliary layer.

Reference will be made in detail to the embodiments of the present invention, and the examples of the embodiments are described in the drawings. In the following descriptions, the terms "on" and "under" are used only to describe a direction, and therefore are not intended to be limited to "directly on" and "directly" ...under".

FIG. 1 is a circuit diagram of a pixel region of an Organic Light-Emitting Diode (OLED) display device according to an embodiment of the invention.

As shown in FIG. 1, an OLED display device according to this embodiment of the present invention includes: a gate line GL; a data line DL; a switching thin film transistor Ts; a driving thin film transistor Td; and a storage capacitor Cst; An organic light-emitting diode De. The gate line GL and the data line DL are interlaced with each other to define a pixel region P. The switching thin film transistor Ts, the driving thin film transistor Td, the storage capacitor Cst, and the organic light emitting diode De are formed in the pixel region P.

In more detail, a gate electrode of the switching thin film transistor Ts is connected to the gate line GL, and a source electrode of the switching thin film transistor Ts is connected to the data line DL. A gate electrode of the driving thin film transistor Td is connected to a drain electrode of the switching thin film transistor Ts, and a source electrode of the driving thin film transistor Td is connected to a high voltage supply terminal VDD. An anode of the organic light-emitting diode De is connected to a drain electrode of the driving thin film transistor Td, and a cathode of the organic light emitting diode De is connected to a low voltage supply terminal VSS. The storage capacitor Cst is connected to the gate electrode of the driving thin film transistor Td and the drain electrode.

The OLED display device is driven to display an image. In more detail, when the switching thin film transistor Ts is turned on by applying a gate signal from the gate line GL, a data signal from the data line DL is applied to the driving thin film transistor Td by the switching thin film transistor Ts. The gate electrode and the electrode of the storage capacitor Cst. When the driving thin film transistor Td is turned on by the data signal, the current flowing through the organic light emitting diode De is controlled to thereby display an image. By coming The organic light emitting diode De emits light from the high voltage supply terminal VDD by driving the current supplied from the thin film transistor Td.

That is, the amount of current flowing through the organic light-emitting diode De is proportional to the magnitude of the data signal, and the intensity of light emitted from the organic light-emitting diode De is proportional to the amount of current flowing through the organic light-emitting diode De. Therefore, depending on the size of the data signal, the pixel area P displays different gradations, and thus the OLED display device displays an image.

When the switching film transistor Ts is turned off, the storage capacitor Cst maintains a picture corresponding to the charge of the data signal. According to this, even if the switching thin film transistor Ts is turned off, the storage capacitor Cst maintains the amount of current flowing through the organic light emitting diode De fixed and the gray scale displayed by the organic light emitting diode De can be maintained before the next screen. .

However, the OLED display device according to this embodiment of the present invention is not limited to this example. Alternatively, at least one transistor, at least one signal line, and/or at least one capacitance for compensation may be further formed in each pixel region.

Fig. 2 is a cross-sectional view showing an OLED display device according to this embodiment of the present invention and showing a pixel region.

In FIG. 2, a semiconductor layer 122 is patterned and the semiconductor layer 122 is formed on an insulating substrate 110. The substrate 110 can be a glass substrate or a plastic substrate. The semiconductor layer 122 may be formed of an oxide semiconductor material. In an OLED display device including a semiconductor layer 122 formed of an oxide semiconductor material, a light-blocking pattern (not shown) and a buffer layer (not shown) are formed under the semiconductor layer 122. The light stop pattern blocks light from the outside or light emitted from a light emitting diode to prevent the semiconductor layer 122 from being degraded by light. Alternatively, the semiconductor layer 122 may be formed of polysilicon, and in this case, impurities may be doped on both sides of the semiconductor layer 122.

A gate insulating layer 130 formed of an insulating material is formed on the semiconductor layer 122 on almost the entire substrate 110. The gate insulating layer 130 may be formed of an inorganic insulating material such as cerium oxide (SiO ₂ ). When the semiconductor layer 122 is formed of polysilicon, the gate insulating layer 130 may be formed of hafnium oxide (SiO ₂ ) or tantalum nitride (SiN _x ).

A gate electrode 132 of a conductive material such as a metal may be formed on the gate insulating layer 130 to correspond to the semiconductor layer 122. In addition, a gate line (not shown) and a first capacitor electrode (not shown) may be formed on the gate insulating layer 130. The gate line is on the first side Extending upwardly, and the first capacitive electrode is connectable to the gate electrode 132.

The OLED display device according to this embodiment of the present invention includes a gate insulating layer 130 formed on almost the entire substrate 110. Alternatively, the gate insulating layer 130 may be patterned to have the same shape as the gate electrode 132.

An insulating layer 140 formed of an insulating material is formed on the gate electrode 132 on almost the entire substrate 110. The mutual insulating layer 140 may be an inorganic insulating material (for example, cerium oxide (SiO ₂ ) and tantalum nitride (SiN _x )) or an organic insulating material (for example, benzocyclobutene and photosensitive acrolein). Photo acryl) is formed.

The mutual insulating layer 140 includes a first contact hole 140a and a second contact hole 140b to expose upper surfaces of both sides of the semiconductor layer 122. The first contact hole 140a and the second contact hole 140b are isolated from the gate electrode 132, and the gate electrode 132 is disposed between the first contact hole 140a and the second contact hole 140b. The first contact hole 140a and the second contact hole 140b are also formed in the gate insulating layer 130. Alternatively, when the gate insulating layer 130 is patterned to have the same shape as the gate electrode 132, the first contact hole 140a and the second contact hole 140b are formed only in the mutual insulating layer 140.

A source electrode 142 and a drain electrode 144, which are one of a conductive material such as a metal, are formed on the mutual insulating layer 140. In addition, a data line (not shown), a power supply line (not shown), and a second capacitor electrode (not shown) may be formed on the mutual insulating layer 140. The data line and the power supply line extend in a second direction.

The source electrode 142 and the drain electrode 144 are spaced apart from each other with respect to the gate electrode 132. The source electrode 142 and the drain electrode 144 are in contact with both sides of the semiconductor layer 122 by the first contact hole 140a and the second contact hole 140b, respectively. The data lines can be interleaved with the gate lines to define the pixel area. In addition, a power supply line that supplies a high level of voltage can be separated from the data line. The second capacitor electrode can be connected to the drain electrode 144, and can overlap the first capacitor electrode to form a storage capacitor. The mutual insulating layer 140 acts as a dielectric substance between the second capacitor electrode and the first capacitor electrode.

In the OLED display device, a thin film transistor includes: a semiconductor layer 122; a gate electrode 132; a source electrode 142; and a drain electrode 144. The thin film transistor may have a coplanar structure in which a gate electrode 132, a source electrode 142, and a drain electrode 144 are disposed on one side of the semiconductor layer 122, that is, in the semiconductor layer Above the 122.

Alternatively, the thin film transistor may have an inverted staggered structure in which a gate electrode is disposed under the semiconductor layer, and a source electrode and a drain electrode are disposed over the semiconductor layer. In this case, the semiconductor layer may be formed of polysilicon.

In addition, the thin film transistor can be a thin film transistor that is one of the OLED display devices. A switching thin film transistor can have the same shape as the driving thin film transistor formed on the substrate 110. At this time, the gate electrode 132 of the driving thin film transistor is connected to a drain electrode of the switching thin film transistor and the source electrode 142 of the driving thin film transistor is connected to the power supply line. In addition, the gate electrode and the source electrode of the switching thin film transistor are respectively connected to the gate line and the data line.

One of the insulating material, a first passivation layer 152 and a second passivation layer 154 are sequentially formed on the source electrode 142 and the drain electrode 144 on almost the entire substrate 110. The first passivation layer 152 may be formed of an inorganic insulating material (for example, hafnium oxide and tantalum nitride), and the second passivation layer 154 may be an organic insulating material (for example, benzocyclobutene and photo-sensitized acrolein). )form. The second passivation layer 154 can have a flat upper surface.

The first passivation layer 152 and the second passivation layer 154 have a drain contact hole 156 exposing the drain electrode 144. In FIG. 2, although the drain contact hole 156 is directly formed on the second contact hole 140b, the drain contact hole 156 may be spaced apart from the second contact hole 140b.

One of the first passivation layer 152 and the second passivation layer 154 may be omitted. For example, a first passivation layer 152 of an inorganic insulating material may be omitted.

A first electrode 162 having a conductive material of a relatively high work function is formed on the second passivation layer 154. The first electrode 162 is disposed in each of the pixel regions and is in contact with the drain electrode 144 through the drain contact hole 156. For example, the first electrode 162 may be formed of a transparent conductive material such as indium tin oxide and indium zinc oxide.

A bank layer 170 of one insulating material is formed on the first electrode 162. The bank layer 170 is disposed between adjacent pixel regions, has an opening exposing the first electrode 162, and an edge covering the first electrode 162.

In the OLED display device, the bank layer 170 has a single layer structure, but the structure of the bank layer 170 is not limited thereto. For example, the bank layer can have a two-layer structure. That is, the bank layer may have a first bank portion and a second bank portion on the first bank portion, and the first bank portion may have a wider width than the second bank portion. At this time, the first bank can have a pro One of an aqueous inorganic insulating material or an organic insulating material is formed, and the second bank portion may be formed of one of organic materials having hydrophobicity.

A light emitting layer 180 is formed on the first electrode 162 exposed by the opening of the bank layer 170. The light emitting layer 180 includes a hole assisting layer 182, a Light-Emitting Material Layer (EML) 184, and an electron assisting layer 186 which are sequentially disposed from an upper surface of the first electrode 162.

The hole assist layer 182, the luminescent material layer 184, and the electron assist layer 186 may be formed of an organic material and may be formed by a solution procedure, which may be referred to as a soluble procedure. According to this, the process can be simplified, and a display device having a large size and high image quality can be provided. One of a spin coating method, an inkjet method, and a screen printing method can be used as a solution program.

Alternatively, the hole assist layer 182, the luminescent material layer 184, and the electron assist layer 186 may be formed by a vacuum evaporation process. Additionally, the hole assist layer 182, the luminescent material layer 184, and the electron assist layer 186 can be formed in a combination of the solution procedure and the vacuum evaporation procedure.

The hole assisting layer 182 may include at least one of a Hole Injecting Layer (HIL) and a Hole Transporting Layer (HTL), and the electron assisting layer 186 may include an electron injecting layer ( Electron Injecting Layer (EIL) and at least one of an Electro Transport Layer (ETL).

A second electrode 192 having a conductive material of a relatively low work function is formed on the electron assist layer 186 on almost the entire substrate 110. Here, the second electrode 192 may be formed of aluminum, magnesium, silver, or an alloy of the metals.

The first electrode 162, the light emitting layer 180, and the second electrode 192 constitute an organic light emitting diode De. The first electrode 162 serves as an anode and the second electrode 192 serves as a cathode. Here, the OLED display device according to the embodiment of the present invention is an active matrix type and a top emission type. In the top emission type, light from the luminescent material layer 184 is output to the outside through the second electrode 192. In this case, the first electrode 162 may further include a reflective layer (not shown) formed of an opaque conductive material. For example, the reflective layer may be formed of an aluminum palladium copper alloy, and the first electrode 162 may have a three-layer structure of indium tin oxide/aluminum palladium copper alloy/indium tin oxide. Further, the second electrode 192 may have a relatively thin thickness to allow light to be transmitted via the second electrode 192. For example, the second electrode 192 can have a transmittance of about 45% to 50%.

An OLED display device according to an embodiment of the invention includes a plurality of pixels, and each pixel includes red, green, and blue sub-pixels. The thin film transistor and the organic light emitting diode system shown in Fig. 2 are formed in each of the red, green, and blue sub-pixel regions.

At this time, the organic light-emitting diodes of the red, green, and blue sub-pixels may have different thicknesses. This will be explained in more detail with reference to the drawings.

Figure 3 is a schematic illustration of red, green, and blue sub-pixels of an OLED display device in accordance with this embodiment of the present invention.

In FIG. 3, the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb are defined on a substrate 110, and an organic light-emitting diode De is disposed in each of the sub-pixel regions Pr, Pg, Pb. The organic light emitting diode De in each of the sub-pixel regions Pr, Pg, and Pb includes a first electrode 162, a light emitting layer 180, and a second electrode 192.

The first electrode 162 can be an anode and can be formed of a conductive material having a relatively high work function. The first electrode 162 may include a transparent conductive material (for example, indium tin oxide and indium zinc oxide). Further, the first electrode 162 may further include a reflective layer at a lowest portion thereof.

Even if the first electrode 162 is connected to each other in the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb, the first electrode 162 has a red sub-pixel region Pr, a green sub-pixel region Pg, and a blue sub-pixel region. Pb is separated from each other.

The light emitting layer 180 is disposed on the first electrode 162 in each of the sub-pixel regions Pr, Pg, and Pb. The light emitting layer 180 includes a hole assisting layer 182, a light emitting material layer 184, and an electron assisting layer 186.

Here, the luminescent material layer 184 of the red sub-pixel region Pr and the green sub-pixel region Pg includes a yellow luminescent material, and the luminescent material layer 184 of the blue sub-pixel region Pb includes a blue luminescent material.

The luminescent material layer 184 can be formed in a solution procedure. Alternatively, luminescent material layer 184 can be formed in a solution procedure as well as a vacuum evaporation procedure. That is, the luminescent material layer 184 of the red sub-pixel region Pr and the green sub-pixel region Pg may be formed by the solution program, and the luminescent material layer 184 of the blue sub-pixel region Pb may be formed by the vacuum evaporation process.

In addition, the hole assist layer 182 may include a hole injection layer and a hole transport layer. At this time, the red sub-pixel area Pr, the green sub-pixel area Pg, and the blue sub-pixel area Pb The hole assist layer 182 can have different thicknesses. More specifically, the thickness of the hole auxiliary layer 182 of the red sub-pixel region Pr is smaller than the thickness of the hole auxiliary layer 182 of the green sub-pixel region Pg, and the thickness of the hole auxiliary layer 182 of the red sub-pixel region Pr is larger than that of the blue sub-pixel The thickness of the hole assisting layer 182 of the pixel region Pb.

The hole assist layer 182 can be formed in the solution procedure, and the thickness of the hole assist layer 182 can be adjusted by varying the amount of the solution dripped.

At the same time, the electron assist layer 186 can include an electron transport layer (ETL). The electron assist layer 186 may further include an electron injection layer on the electron transport layer. The electron assist layer 186 can be formed in this vacuum evaporation process.

The second electrode 192 as a cathode is provided on the light-emitting layer 180 of the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb. The second electrode 192 may be formed of aluminum, magnesium, silver, or an alloy of the metals. The second electrode 192 can have a relatively thin thickness to allow light to pass through the second electrode 192.

A cladding layer 200 is formed on the organic light-emitting diode De to protect the organic light-emitting diode De from external moisture or oxygen. The coating layer 200 may be formed by a UV sealer or a glass material sealant. Alternatively, the cladding layer 200 may be formed of an inorganic layer and an organic layer which are alternately disposed.

A color filter layer 220 is disposed on the cladding layer 200. The color filter layer 220 may include a red color filter layer Rc, a green color filter layer Gc, and a blue color filter layer Bc corresponding to the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb. Here, the blue color filter layer Bc can be omitted.

An outer cover (not shown) may be further formed between the cover layer 200 and the color filter layer 220 to protect the cover layer 200 and to flatten an upper surface.

An opposite substrate 210 is disposed on the color filter layer 220. The opposite substrate 210 can be a glass substrate or a plastic substrate.

Here, the color filter layer 220 may be formed on the opposite substrate 210, and the opposite substrate 210 including the color filter layer 220 thereon may be connected to the substrate 110 including the organic light emitting diode De.

The OLED display device according to an embodiment of the present invention is a top emission type in which light from the light-emitting layer 180 is output to the outside through the second electrode 192.

As described above, in the OLED display device according to the embodiment of the invention, the organic light-emitting diodes De of the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb have different element thicknesses. That is, each of the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb of the organic light-emitting diode De has a lower surface from the first electrode 162 and a lower surface of the second electrode 192. When the distance is a component thickness, the thickness of the element of the organic light-emitting diode De of the red sub-pixel region Pr is smaller than the thickness of the element of the organic light-emitting diode De of the green sub-pixel region Pg, and the organic light emission of the red sub-pixel region Pr The thickness of the element of the diode De is greater than the thickness of the element of the organic light-emitting diode De of the blue sub-pixel region Pb.

At this time, by making the thickness of the light-emitting layer 180 different, in particular, the thickness of the hole auxiliary layer 182 is different, and the organic light-emitting diodes of the red sub-pixel region Pr, the green sub-pixel region Pg, and the blue sub-pixel region Pb are different. Can be different from each other. That is, the thickness of the hole auxiliary layer 182 of the red sub-pixel region Pr is formed to be smaller than the thickness of the hole auxiliary layer 182 of the green sub-pixel region Pg and larger than the thickness of the hole auxiliary layer 182 of the blue sub-pixel region Pb.

The thickness of the hole assist layer 182 can be determined by considering a microcavity effect.

Figure 6A is a diagram showing the CIE x color coordinates according to the thickness of the hole auxiliary layer, and Figure 6B is a diagram showing the CIE y color coordinates according to the thickness of the hole auxiliary layer, and Figure 6C is based on the hole auxiliary layer. The thickness shows a pattern of current efficiency. In FIGS. 6A to 6C, in order to obtain a relatively high current efficiency and satisfy a desired color coordinate, the thickness of the hole auxiliary layer 182 of the red sub-pixel region Pr is smaller than the hole auxiliary layer 182 of the green sub-pixel region Pg. The thickness is ideal. In particular, the hole assisting layer 182 of the red sub-pixel region Pr has a thickness corresponding to a second order cavity condition and the hole auxiliary layer 182 of the green sub-pixel region Pg has a corresponding to a third-order cavity condition. The thickness is advantageous. As described above, the hole assisting layer 182 includes at least one of a hole injection layer and a hole transport layer, and the total thickness of the hole injection layer and the hole transport layer becomes the thickness of the hole auxiliary layer 182. . Therefore, the total thickness of the hole injection layer and the hole transport layer in the red sub-pixel region Pr corresponds to the second-order cavity condition, and the total of the hole injection layer and the hole transport layer in the green sub-pixel region Pg. The thickness corresponds to the third-order cavity condition. If the hole auxiliary layer 182 of the red sub-pixel region Pr has a thickness corresponding to a lower-order cavity condition lower than the second-order cavity condition Degree, the lifetime of the organic light-emitting diode is lowered, and if the hole assisting layer 182 of the green sub-pixel region Pg has a thickness corresponding to a higher-order cavity condition higher than the third-order cavity condition, the driving voltage is increased. . For example, the hole assist layer 182 of the red sub-pixel region Pr may have a thickness of 250 nm to 280 nm, and the hole auxiliary layer 182 of the green sub-pixel region Pg may have a thickness of 310 nm to 330 nm. At this time, if the thickness of the hole auxiliary layer 182 in each of the red sub-pixel region Pr and the green sub-pixel region Pg is out of the above range, the yellow light is mixed in each of the red sub-pixel region Pr and the green sub-pixel region Pg and It is omitted and the color coordinates do not correspond.

Meanwhile, the hole auxiliary layer 182 of the blue sub-pixel region Pb may have a thickness of 30 nm to 70 nm.

At this time, the thickness of the hole auxiliary layer 182 can be changed by controlling the thicknesses of the red sub-pixel region Pr, the green sub-pixel region Pg, the hole injection layer HIL of the blue sub-pixel region Pb, and the hole transport layer HTL. In general, since the carrier mobility of the hole transport layer HTL is larger than the carrier mobility of the hole injection layer HIL, it is advantageous that the thickness of the hole transport layer HTL is changed to be lower than the thickness of the hole injection layer HIL.

Meanwhile, as described above, the luminescent material layer 184 of the red sub-pixel region Pr and the green sub-pixel region Pg of the organic light-emitting diode De includes a yellow luminescent material. The yellow luminescent material has a relatively long lifetime and emits yellowish red or yellowish green light by the microcavity effect.

Accordingly, the OLED display device according to an embodiment of the present invention can generate red light and green light by using a yellow luminescent material, a micro cavity effect, and a color filter layer.

Figure 4 is a schematic cross-sectional view showing light output from an OLED display device in accordance with this embodiment of the present invention. 5A is a spectral diagram of light emitted from a red and green sub-pixel region of an organic light emitting diode of an OLED display device according to the embodiment of the present invention, and FIG. 5B is an OLED according to the embodiment of the present invention. The spectral pattern of the light output in the red and green sub-pixel regions of the display device.

In FIG. 4, FIG. 5A, and FIG. 5B, the luminescent material layer 184 of the red sub-pixel region Pr and the green sub-pixel region Pg includes a yellow luminescent material, and the yellow luminescent material includes a first emission peak and a first Two emission peaks. At this time, the yellow luminescent material may have a first emission peak in a wavelength range of 530 nm to 555 nm and at 590 nm to A second emission peak in the wavelength range of 620 nm. For example, the yellow luminescent material may include 4,4'-N,N'-dicarbazole-biphenyl (4,4'-N,N'-dicarbazole-biphenyl) and may also include two [2-(4- Third butylphenyl)benzothiazolyl-N,C2'] bis[2-(4-tertbutylphenyl)benzothiazolato-N,C2']iridium(acetylactonate)[(t-bt)2Ir( Acac)]) as a dopant.

Here, in the red sub-pixel region Pr, the luminescent material layer 184 including the yellow luminescent material emits orange light, that is, yellowish red light Ry due to the micro cavity effect. The yellowish red light Ry passes through the red color filter layer Rc to thereby output a deep red light R.

Further, in the green sub-pixel region Pg, the luminescent material layer 184 including the yellow luminescent material emits yellowish green light Gy because of the microcavity effect. The yellowish green light Gy passes through the green color filter layer Gc to thereby output a dark green light G.

At this time, in the blue sub-pixel region Pb, the luminescent material layer 184 includes a blue luminescent material and emits blue light B due to the microcavity effect. The blue light B passes through the blue color filter layer Bc to thereby output a deep blue light B.

In this manner, the OLED display device according to the present invention generates deep red light and dark green light by applying a yellow light-emitting material having a relatively long lifetime to the red sub-pixel region Pr and the green sub-pixel region Pg, and uses a micro cavity effect. And a color filter layer to generate red light and green light. Therefore, the lifetimes of the organic light-emitting diodes of the red sub-pixel region Pr and the green sub-pixel region Pg can be increased.

Further, the OLED display device according to an embodiment of the present invention can omit a polarizer because of the micro cavity effect, thereby reducing the cost.

Even if the OLED display device in the above embodiment is a top emission type, the OLED display device may be a bottom emission type.

Various modifications and variations of the display device of the present invention can be made by those skilled in the art without departing from the scope and spirit of the invention. Therefore, the present invention can be applied to the modifications and variations as long as they are within the scope of the appended claims.

The present application claims priority to Korean Patent Application No. 10-2015-0190204, filed on Dec. 30, 2015, the disclosure of which is hereby incorporated by reference.

110‧‧‧Substrate

162‧‧‧first electrode

180‧‧‧Lighting layer

182‧‧‧ hole auxiliary layer

184‧‧‧ luminescent material layer

186‧‧‧Electronic auxiliary layer

192‧‧‧second electrode

200‧‧‧ coating

210‧‧‧relative substrate

220‧‧‧Color filter layer

Bc‧‧‧Blue color filter layer

De‧‧‧Organic Luminescent Diode

Gc‧‧‧Green color filter

Pb‧‧‧ blue sub-pixel area

Pg‧‧‧Green sub-pixel area

Pr‧‧‧Red sub-pixel area

Rc‧‧‧Red color filter

Claims (11)

An organic light emitting diode display device includes: a substrate on which a red sub-pixel region, a green sub-pixel region, and a blue sub-pixel region are defined; and a plurality of first electrodes respectively in the red sub-pixel region The green sub-pixel region and the blue sub-pixel region; a first luminescent layer, a second luminescent layer, and a third luminescent layer, the luminescent layers are located on the first electrodes and respectively a red sub-pixel region, the green sub-pixel region, and the blue sub-pixel region; a second electrode on the first luminescent layer, the second luminescent layer, and the third luminescent layer; and a red color a filter layer, a green color filter layer, and a blue color filter layer, the color filter layers are located on the second electrode and correspond to the red sub-pixel region, the green sub-pixel region, and the a blue sub-pixel region, wherein the thickness of the first luminescent layer is less than the thickness of the second luminescent layer. The organic light emitting diode display device of claim 1, wherein the third light emitting layer comprises a blue light emitting material. The organic light emitting diode display device according to claim 1, wherein the thickness of the third light emitting layer is smaller than the thickness of the first light emitting layer. The organic light emitting diode display device of claim 1, wherein the first light emitting layer and the second light emitting layer each comprise a yellow light emitting material. The organic light emitting diode display device of claim 4, wherein the yellow light emitting material has a first emission peak and a second emission peak, and the first emission peak is in a wavelength range of 530 nm to 555 nm. The middle and the second emission peak are in a wavelength range of 590 nm to 620 nm. The organic light emitting diode display device according to claim 4, wherein the yellow light emitting material comprises 4,4'-N,N'-dicarbazole-biphenyl and also includes two [2-(4) -T-butylphenyl)benzothiazolyl-N,C2']acetamidineacetone as a dopant. The OLED display device of claim 1, wherein the first luminescent layer and the second luminescent layer each comprise a hole assisting layer, a luminescent material layer, and an electron assisting layer. And wherein the thickness of the hole auxiliary layer of the first light emitting layer is smaller than the thickness of the hole auxiliary layer of the second light emitting layer. The organic light emitting diode display device according to claim 7, wherein the thickness of the hole auxiliary layer of the first light emitting layer corresponds to a second-order resonant cavity condition, and the electricity of the second light emitting layer The thickness of the hole auxiliary layer corresponds to a third-order resonant cavity condition. The organic light emitting diode display device of claim 7, wherein the hole auxiliary layer of the first light emitting layer has a thickness of 250 nm to 280 nm, and the hole auxiliary layer of the second light emitting layer The thickness is from 310 nm to 330 nm. The organic light emitting diode display device of claim 2, wherein the third light emitting layer comprises a hole assisting layer, a light emitting material layer, and an electron assisting layer, and wherein The thickness of the hole auxiliary layer of the third light emitting layer is smaller than the thickness of the hole auxiliary layer of the first light emitting layer. The organic light emitting diode display device according to claim 10, wherein the hole auxiliary layer of the third light emitting layer has a thickness of 30 nm to 70 nm.