KR20140086124A - Organic light emitting diodes - Google Patents

Abstract

The present invention relates to an organic light emitting device and, more particularly, to an organic light emitting device capable of improving color reproduction and luminous efficiency and increasing a lifetime thereof. The feature of the present invention is to emit white light (W) by a first light emitting layer which emits blue light and a second light emitting layer which emits red and green light. Thereby, luminous efficiency is improved by implementing an improved microcavity effect. The color reproduction is improved by preventing red and green color losses. Therefore, the luminous efficiency and lifetime of an OLED are improved.

Description

[0001] The present invention relates to organic light emitting diodes

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic light emitting device, and more particularly, to an organic light emitting device having improved color reproducibility, luminous efficiency, and lifetime.

Until recently, CRT (cathode ray tube) was mainly used as a display device. However, a flat panel display device such as a plasma display panel (PDP), a liquid crystal display device (LCD), and an organic light emitting diode (OLED) Have been widely studied and used.

Among the above flat panel display devices, an organic light emitting element (hereinafter referred to as OLED) is a self-light emitting element, and a backlight used in a liquid crystal display device which is a non-light emitting element is not required.

In addition, it has a better viewing angle and contrast ratio than liquid crystal display devices, is advantageous in terms of power consumption, can be driven by DC low voltage, has a fast response speed, is resistant to external impacts due to its solid internal components, It has advantages.

Particularly, since the manufacturing process is simple, it is advantageous in that the production cost can be saved more than the conventional liquid crystal display device.

The OLED is a self-luminous element that emits light through the organic electroluminescent diode, and the organic electroluminescent diode emits light through the organic electroluminescent phenomenon.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a band diagram of an organic light emitting diode having an emission principle based on a general organic light emitting phenomenon.

As shown in the figure, the organic light emitting diode 10 includes an anode and a cathode 21, a hole transport layer (HTL) 33 located therebetween, and an electron transport layer And an emission material layer (EML) 40 interposed between the hole transport film 33 and the electron transport film 35.

A hole injecting layer (HIL) 37 is interposed between the anode electrode 21 and the hole transporting layer 33 to improve the luminous efficiency. The cathode electrode 25 and the electron transporting layer 35 are interposed between the anode electrode 21 and the hole transporting layer 33, An electron injection layer (EIL) 39 is interposed therebetween.

When the positive and negative voltages are applied to the anode electrode 21 and the cathode electrode 25, the organic light emitting diode 10 has the positive holes of the anode electrode 21 and the positive electrode of the cathode electrode 25, Electrons are transported to the light-emitting film 40 to form excitons. When the excitons are transited from the excited state to the ground state, light is generated and is emitted by the light-emitting film 40 in the form of visible light.

Recently, a hybrid type white organic light emitting diode (LED) 10 using a fluorescent material and a phosphor simultaneously has been developed. Such a hybrid type white organic light emitting diode 10 includes a light emitting layer 40, a white light W is realized by mixing blue, yellow and green.

However, in order to realize the white light W, the light emitting method of mixing the three wavelength lights of blue, green and red is most ideal. Therefore, instead of red, Green), the color reproduction rate is low due to low transmittance of light in the red wavelength band after passing through the color filter.

It is an object of the present invention to provide an OLED capable of significantly increasing lifetime and efficiency and satisfying a color reproduction rate.

According to an aspect of the present invention, there is provided a liquid crystal display comprising: a first electrode including a reflective layer; A first hole transport layer located above the first electrode; A first luminescent layer located above the first hole transporting layer and emitting blue color; A first electron transport film located above the first light emitting film; A charge generation film located above the first electron transport film; A second hole transport film located above the charge generation film; A second light emitting film located on the second major transport film and emitting red and green colors; A second electron transport film located on the second light emitting film; And a second electrode disposed on the second electron transport layer and having a semi-transparent property, wherein the first and second light emitting layers provide a micro cavity effect.

At this time, the distance between the first electrode and the second electrode is 200 to 400 nm. The first electrode is formed of a double layer of the reflective layer and the transparent layer and the reflective layer is formed of one selected from the group consisting of aluminum (Al), tantalum (Ta), silver (Ag), aluminum alloy (AlNd) Lt; / RTI >

The second electrode may be formed of one selected from aluminum (Al), aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold (Au), aluminum magnesium alloy (AlMg), silver silver alloy And a hole injecting film is interposed between the first electrode and the first hole transporting film and an electron injecting film is interposed between the second electrode and the second electron transporting film.

According to another aspect of the present invention, there is provided a liquid crystal display comprising: a first substrate on which driving thin film transistors are formed for R, G, and B subpixels; And a second light-emitting film formed in the R, G, and B sub-pixels on the first substrate, the first light-emitting film emitting a blue color, and the second light-emitting film emitting red and green colors, An electroluminescent diode; And a second substrate bonded to the first substrate so as to be spaced apart from the first substrate. The first light-emitting film and the second light-emitting film provide a micro-cavity effect.

The organic light emitting diode includes a first electrode including a reflective layer, a first hole transport layer located above the first electrode, a first light emitting layer located above the first hole transport layer, A first electron transport film located above the first light emitting film, a charge generation film located above the first electron transport film, a second hole transport film located above the charge generation film, A second light emitting film located on the upper portion of the film, a second electron transport film located above the second light emitting film, and a second electrode disposed on the upper portion of the second electron transport film and being translucent, 1 and the second electrode is different for each of the R, G, and B sub-pixels.

Also, the distance between the first and second electrodes is the same in the R and G subpixels, the B subpixels are different, and the R, G, and B subpixels include R, G, And the organic light emitting diode emits white light (W).

An adhesive layer is provided on the passivation layer, and the second substrate is bonded to the first substrate through the adhesive layer.

As described above, the organic electroluminescent diode according to the present invention is characterized in that the organic electroluminescent diode is divided into a first luminescent layer emitting a blue color and a second luminescent layer emitting a red- And the white light W is emitted through the two light emitting films, thereby achieving a further improved micro-cavity effect, thereby improving the light efficiency.

In addition, it is possible to prevent loss of red and green colors from occurring, thereby improving the color reproduction rate.

Therefore, the light emitting efficiency and lifetime of the OLED can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a band diagram of an organic light emitting diode having an emission principle by a general organic light emitting phenomenon. FIG.
Figure 2 schematically illustrates a cross-section of an OLED according to an embodiment of the present invention.
FIG. 3 is a simplified view illustrating a cross-sectional structure of an organic light emitting diode according to a first embodiment of the present invention. FIG.
FIG. 4 is a band diagram of the organic light emitting diode of FIG. 3; FIG.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

2 schematically shows a cross section of an OLED.

The OLED 100 according to the present invention includes a substrate 101 on which a driving and switching thin film transistor DTr (not shown) and an organic light emitting diode E are formed, an encapsulation substrate 102 for encapsulation ).

The OLED 100 includes a plurality of subpixels SP and a plurality of subpixels R-SP, G-SP, and B-SP. The semiconductor layer 103 is made of silicon and its central portion is composed of source and drain regions 103b and 103c doped with impurities at high concentration on both sides of the active region 103a and the active region 103a .

A gate insulating layer 105 is formed on the semiconductor layer 103.

The gate electrode 107 and the gate wiring extending in one direction are formed on the gate insulating film 105 in correspondence with the active region 103b of the semiconductor layer 103 and not shown in the drawing.

The first interlayer insulating film 109a and the gate insulating film 105 under the first interlayer insulating film 109a are formed on the upper surface of the gate electrode 107 and the gate wiring (not shown) And first and second semiconductor layer contact holes 111a and 111b that respectively expose source and drain regions 103a and 103c located on both sides of the semiconductor layer 103b.

Next, upper portions of the first interlayer insulating film 109a including the first and second semiconductor layer contact holes 111a and 111b are separated from each other by a source exposed through the first and second semiconductor layer contact holes 111a and 111b, And source and drain electrodes 113 and 115 which are in contact with the source and drain regions 103a and 103c, respectively.

And a drain contact hole 117 exposing the drain electrode 115 to the upper portion of the first interlayer insulating film 109a exposed between the source and drain electrodes 113 and 115 and the two electrodes 113 and 115, An insulating film 109b is formed.

At this time, the semiconductor layer 103 including the source and drain electrodes 113 and 115 and the source and drain regions 103a and 103c contacting the electrodes 113 and 115 and the gate insulating film The gate electrode 105 and the gate electrode 107 constitute a driving thin film transistor DTr.

Although not shown in the drawings, data lines (not shown) for defining the sub-pixels R-SP, G-SP, and B-SP intersect the gate wiring (not shown). The switching thin film transistor (not shown) has the same structure as the driving thin film transistor DTr and is connected to the driving thin film transistor DTr.

In the drawing, the switching thin film transistor (not shown) and the driving thin film transistor DTr are shown as an example of a top gate type in which the semiconductor layer 103 is a polysilicon semiconductor layer. As a variation thereof, It may be formed as a bottom gate type of impurity amorphous silicon.

The first electrode 211, the organic light emitting layer 213, and the second electrode 215 constituting the organic electroluminescent diode E are sequentially formed on the second interlayer insulating film 109b, Respectively.

Here, the first electrode 211 is connected to the drain electrode 115 of the driving thin film transistor DTr through the drain contact hole 117 of the second interlayer insulating film 109b.

In such a case, the first electrode 211 serves as an anode electrode, and the second electrode 215 serves as a cathode.

Here, the organic light emitting layer 213 is composed of a hole transport film (221a and 221b in FIG. 3), a light emitting film (223a and 223b in FIG. 3), and an electron transport film (225a and 225b in FIG. 3).

The organic light emitting layer 213 emits white light W.

The OLED 100 may apply a predetermined voltage to the first electrode 211 and the second electrode 215 in accordance with the selected color signal to cause the holes injected from the first electrode 211 and the holes injected from the second electrode 215 The excited electrons are transported to the organic light emitting layer 213 to form an exciton. When the excitons transit from the excited state to the ground state, light is emitted and emitted in the form of visible light.

At this time, the light emitted from the organic light emitting layer 213 passes through the second electrode 215 and exits to the outside, so that the OLED 100 implements the image by the top emission method.

The first electrode 211 is formed for each of the subpixels R-SP, G-SP, and B-SP. The first electrode 211 is formed for each of the subpixels R- And a bank (bank 119) is located between the banks 211.

That is, the first electrode 211 is divided into sub-pixels (R-SP, G-SP, and B-SP) with the bank 119 as a boundary for each of the subpixels R- And is formed in a separated structure.

A passivation layer 120 in the form of a thin film is formed on the driving thin film transistor DTr and the organic light emitting diode E. The passivation layer 120 is formed on the organic light emitting diode E to protect the driving thin film transistor DTr and the organic electroluminescent diode E formed on the substrate 101. The organic electroluminescent diode E is surrounded by the substrate 101, As shown in FIG.

R (red), G (green), and B (blue) color filters 140a, 140b, and 140c are formed on the passivation layer 120 for each of the subpixels R-SP, G- Respectively.

Therefore, the OLED 100 of the present invention emits R, G, and B colors for each of the subpixels (R-SP, G-SP, and B-SP) to realize full color.

As described above, the in-cap substrate 102 is provided above the R, G, and B color filters 140a, 140b, and 140c, and the substrate 101 and the in-cap substrate 102 are bonded to each other through the adhesive layer 130 having adhesive properties. So that they are spaced apart.

Thereby, the OLED 100 is encapsulated.

At this time, in addition to the role of attaching and fixing the in-cap substrate 102, the adhesive layer 130 serves to prevent moisture and contaminants from penetrating into the OLED 100 from the outside.

Therefore, the OLED 100 according to the present invention can prevent a contaminant such as moisture or gas from penetrating from the outside into the OLED 100 through the adhesive layer 130, and even if a contaminant flows into the adhesive layer 130, The contamination source can be prevented from penetrating into the driving thin film transistor DTr and the organic light emitting diode E through the passivation layer 120.

In the OLED 100 according to the present invention, the white light emitted from the organic light emitting layer 213 is transmitted through the R, G, and B color filters 140a, 140b, and 140c.

Particularly, the OLED 100 according to the present invention has improved color reproducibility as compared with the conventional OLED 100, and the luminous efficiency and lifetime of the OLED 100 are also improved compared with the conventional OLED 100 because the organic light emitting layer 213 of the organic light- The light emitting efficiency of the light emitting diode is improved.

3 is a view illustrating a simplified cross-sectional structure of an organic light emitting diode according to an embodiment of the present invention.

The organic light emitting diode E includes a first electrode 211 that is an anode electrode, a second electrode 215 that is a cathode electrode, and a second electrode 213 that is a cathode electrode. And a second stack 229b including a first stack 229a, a charge generation layer (CGL) 227, and a second stack 229b stacked between the first electrode 211 and the second electrode 215. [ (213).

Here, holes and electrons are injected through the charge generation film 227 through the adjacent second hole transporting film 221b and the first electron transporting film 225a of the first and second stacks 229a and 229b, respectively, 223a, and 223b.

At this time, the charges generated in the charge generation film 227 are combined with the holes and electrons injected from the first electrode 211 and the second electrode 215 to emit light.

At this time, the charge generating film 227 can use various organic materials having strong electron donor and electron acceptor characteristics. Basically all materials used for P-type and N-type bonding are available. The charge generation film 227 is preferably formed of P-type and N-type organic semiconductors in order to facilitate the deposition and improve the interfacial characteristics.

A P-type organic semiconductor is a donor capable of absorbing light to form an exciton and to separate electrons into holes and electrons at junctions with N-type organic semiconductors.

At this time, the N type organic semiconductor can be a material that can accept electrons easily, that is, a material that can be easily reduced as an acceptor.

The first stack 229a includes a first hole transport layer (HTL) 221a, a first light emitting layer 223a, a first electron transport layer 223b, and a second electron transport layer 223b between the first electrode 211 and the charge generation layer 227. [ And a second stack 229b are sequentially stacked between the charge generating film 227 and the second electrode 215. The second stack 229b includes a second hole transporting film 221b, A second light emitting film 223b, and a second electron transport film 225b are stacked.

In this case, a hole injection layer (HIL) is interposed between the first electrode 211 and the first hole transporting film 221a to improve luminous efficiency, and the second electrode 215 and the second hole transporting film An electron injection layer (EIL) may be interposed between the first and second electrodes 225a and 225b.

The first electrode 211 is formed of a double layer of a reflective layer 211a and a transparent layer 211b. The reflective layer 211a may be formed of aluminum (Al), tantalum (Ta), silver (Ag) , An Ag alloy, or the like.

The transparent layer 211b is formed of a transparent conductive material having a relatively large work function value such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) so that the first electrode 211 functions as an anode electrode. As shown in Fig.

The second electrode 215 is made of a semitransparent material. The second electrode 215 is formed of a transparent conductive material on a semi-transparent metal film having a work function value lower than that of the first electrode 211 by thinly depositing a metal material. Layer structure in which a thick film is deposited.

The second electrode 215 may be formed of one selected from the group consisting of aluminum (Al), aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold (Au), aluminum magnesium alloy (AlMg) As shown in Fig.

Therefore, the organic electroluminescent diode E of the present invention realizes a micro cavity effect.

Here, the micro cavity effect is a phenomenon in which light reflected from the mirror and the mirror is canceled or interferes with each other, so that only light of a certain wavelength is maintained and the remaining wavelengths are canceled to weaken the intensity of light, The effect is to enhance the specific wavelength.

Such a micro-cavity effect can improve the light efficiency according to the distance between the mirrors and the distance between the mirror and the light emitting films 223a and 223b.

That is, the light emitted from the first and second light emitting films 223a and 223b is externally displayed through the second electrode 215. Since the second electrode 215 has a transflective property, And is directed to the first electrode 211 again.

As described above, light is repeatedly reflected between the first electrode 211 and the second electrode 215. This is called a microcavity effect, and the first electrode 211 and the second electrode 215 The light is repeatedly reflected in the cavity between the light emitting diodes 215 and 215 to improve the light efficiency.

The distance between the first electrode 211 and the second electrode 215 is 200 to 400 nm so that the first and second light emitting films 223a and 223b of the organic electroluminescent diode E Both can implement micro cavity effects.

Accordingly, the organic electroluminescent diode (E) of the present invention is improved in light efficiency.

Here, the first light emitting layer 223a is a light emitting layer containing a dopant of a blue (B) component in one host of blue (B) light, and the second light emitting layer 223b is a light emitting layer containing red (R) ) Dopant (Red + Green) are doped together.

That is, the organic electroluminescent diode (E) of the present invention has a light emission characteristic of blue and red + green.

Therefore, when the OLED (100 in FIG. 2) including the organic electroluminescent diode E of the present invention is driven, light emitted from the first light emitting film 223a and the light emitted from the second light emitting film 223b is mixed with the white light W ) Will be implemented.

Particularly, the organic electroluminescent diode E of the present invention is formed by a first light emitting film 223a emitting a blue color and a second light emitting film 223b emitting a red green color , And the light of three wavelengths of blue, red, and green, which is ideal when the white light W is implemented, is emitted.

Therefore, the white light W realized through the OLED 100 of the present invention is a white light W having a wide wavelength band of 450 to 650 nm including a blue, a red, and a green .

Therefore, the organic electroluminescent diode E of the present invention can emit white light (e.g., red light) by mixing blue light and red green light emitted from the first light emitting film 223a and the second light emitting film 223b The white light W improves the color reproduction ratio as compared with the conventional white light which is realized by mixing blue, yellow and green.

4 is a graph illustrating emission spectra of an organic light emitting diode according to an exemplary embodiment of the present invention.

Here, CF_Green represents the wavelength spectrum of the G (green) color filter (140b in FIG. 2) and CF_Red represents the wavelength spectrum of the R (red) color filter (140a in FIG. 2).

C1 represents a spectrums of wavelengths of organic light emitting diodes which emit white light W by mixing blue, yellow and green, and C2 represents a spectrum according to an embodiment of the present invention Spectrum of an organic electroluminescent diode (E of FIG. 3) that implements white light W through a blue (B) luminescent film and a red (R) and green (G) luminescent film.

Referring to FIG. 4, it can be seen that C1 includes light in the wavelength range not overlapping with the wavelength spectrum of the G (green) color filter (140b in FIG. 2) and the R (red) color filter (G) (green) color filter (see FIG. 2) in the process of transmitting the white light W of C1 through the G (green) color filter (140b in FIG. 2) and the R (Red) color filter (140b in FIG. 2) and the R (red) color filter (140b in FIG. 2) The transmissivity of the light passing through the light-emitting layer 140a is low, and the color of red and green is lost.

This results in loss of light of red and green, and the color reproduction rate is lowered.

In particular, C1 has a very low transmittance of light passing through the R (red) color filter (140a in Fig. 2).

On the other hand, C2 has a larger area overlapping with the G (green) color filter (140b in FIG. 2) and the R (red) color filter (140a in FIG. 2) (Green) color filter (140b in FIG. 2) and R (red) color filter in comparison with C1 in the process of transmitting the red (rust) color filter (140b in FIG. 2) It is possible to prevent loss of green and red since the filter 140a of FIG. 2 is more transmitted, and the color of red and green is improved.

Therefore, the color reproduction ratio of red (Red) and green (Green) is improved.

At this time, by preventing light from being lost, the luminous efficiency of the organic electroluminescent diode (E in FIG. 3) is further increased.

This also improves the luminous efficiency and lifetime of the OLED (100 in FIG. 2).

As described above, the OLED (100 in FIG. 2) of the present invention includes a first light emitting film (223a in FIG. 3) emitting blue color and a second light emitting film It is possible to realize a more improved micro-cavity effect by preventing the white light W from being emitted through the light source 223b (FIG. 3), and it is possible to prevent loss of red and green colors, .

Thus, the light emitting efficiency of the organic light emitting diode (E of FIG. 3) can be improved, and the luminous efficiency and lifetime of the OLED (100 of FIG. 2) can be further improved.

FIG. 5A is a spectrum of each wavelength according to the micro-cavity effect of an organic light emitting diode that implements white light W by mixing blue, yellow and green, FIG. 5B illustrates a first light emitting layer (223a in FIG. 3) emitting a blue color and a second light emitting layer (FIG. 3B) emitting red green 3) of a color filter (140a, 140b, 140c in FIG. 2) in accordance with the micro-cavity effect of the organic electroluminescent diode (E in FIG. 3) Respectively.

First, referring to FIGS. 5A and 5B, it can be confirmed that the intensity of each wavelength is increased by implementing the micro-cavity effect.

That is, it can be seen that the luminous efficiency of the white light W realized through the organic electroluminescent diode (E in FIG. 3) is improved through the micro-cavity effect.

Table 1 below shows the results of simulation in which the luminous efficiency of the white light W is measured by the micro-cavity effect shown in Figs. 5A and 5B.

Red Green Blue B + YG_microcavity 32.6% 59.8% 164.3% B + RG_microcavity 34.2% 113% 167%

Referring to Table 1, the luminous efficiency of the white light W of the organic light emitting diode in which the blue light, the yellow light and the green light are mixed to realize the white light W is compared with the light emitting efficiency of the present invention The white light W is emitted through a first light emitting film (223a in FIG. 3) emitting blue color and a second light emitting film (223b in FIG. 3) emitting red green (Green + It can be seen that the luminous efficiency of the white light emission of the organic electroluminescent diode (E in FIG. 3) to be realized is further improved.

In other words, compared to an organic light emitting diode that emits white light W by mixing blue, yellow, and green, a first light emitting diode emitting blue light according to an embodiment of the present invention The organic light emitting diode (E in FIG. 3) implementing the white light W through the film (223a in FIG. 3) and the second light emitting film (223b in FIG. 3) It can be confirmed that the light emitting efficiency is further improved even if the micro cavity effect is implemented.

This is because the first light emitting film (223a in FIG. 3) emitting blue light according to the embodiment of the present invention by mixing blue, yellow and green, G (green), and B (blue) through a second light emitting film (223b in FIG. 3) that emits red light (green light) 140a, 140b, and 140c, the light transmittance is improved and light can be prevented from being lost.

That is, the emission spectrum of FIG. 5B according to the embodiment of the present invention is compared to FIG. 5A, and it can be seen that the spectrum of the red wavelength range of D_Red in FIG. 5A is low.

When the white light W emitted from the organic electroluminescent diode passes through the R (red), G (green) and B (blue) color filters (140a, 140b and 140c in FIG. 2) Means that the transmittance of light passing through the color filter (140a in Fig. 2) is low.

This means that the color of red is lost much, and therefore the color reproduction rate is lowered.

On the other hand, it can be seen that the spectrum of the red (REd) wavelength band of E3 in FIG. 5B is higher than that of the red wavelength band of D_Red of FIG. 5A.

This means that the white light W emitted from the organic electroluminescent diode (E in FIG. 3) according to the embodiment of the present invention has improved transmittance of light passing through the R (red) color filter (140a in FIG. 2).

Therefore, it is possible to prevent the loss of color of red, thereby improving the color reproducibility and further increasing the luminous efficiency of the organic electroluminescent diode (E in FIG. 3).

As a result, the luminous efficiency of the OLED (100 in FIG. 2) is improved and the lifetime of the OLED (100 in FIG. 2) is also improved as the luminous efficiency is improved. Meanwhile, the organic light emitting diode (E in FIG. 3) according to the embodiment of the present invention may implement the white light W realized through the organic light emitting diode (E in FIG. 3) through the micro cavity effect, The micro-cavity effect may be implemented for each sub-pixel (R-SP, G-SP, B-SP in FIG. 2).

That is, since the wavelengths of light realized through the R, G, and B subpixels (R-SP, G-SP, and B-SP in FIG. 2) (FIG. 3) 211 and the second electrode (215 in FIG. 3) of the organic light emitting diode (E in FIG. 3) 2 R-SP, G-SP, and B-SP).

That is, the first electrode (211 in FIG. 3) and the second electrode (215 in FIG. 3) in the R subpixel (R-SP in FIG. 2) 3) and the second electrode (215 in FIG. 3) in the B sub-pixel (B-SP in FIG. 2) which realizes the blue color having the shortest wavelength, (G-SP in FIG. 2) that is arranged to be spaced apart from the first electrode (211 in FIG. 3) and the second electrode (215 in FIG. 3) The second distance may be smaller than the first distance and larger than the third distance.

Alternatively, the first distance may be the same as the second distance, and the third distance may be different from the first distance. In addition, the first distance may be different from the third distance, and each R, G, and B subpixels (R-SP, G- The distance between one electrode (211 in FIG. 3) and the second electrode (215 in FIG. 3) can be variously adjusted according to the color characteristics, so that a desired micro-cavity effect can be realized.

That is, the OLED according to the embodiment of the present invention (100 in FIG. 2) realizes white light of high efficiency through the micro-cavity effect in the process of realizing the white light W of the organic light emitting diode By adjusting the distance between the first electrode (211 in FIG. 3) and the second electrode (215 in FIG. 3) for each of the R, G and B subpixels (R-SP, G-SP and B- , The micro-cavity effect can be further improved. As described above, the OLED (100 in FIG. 2) according to the embodiment of the present invention includes the first light emitting film (223a in FIG. 3) emitting blue color and the first light emitting film By making the white light W through the second light emitting film 223b in FIG. 3, a further improved micro cavity effect can be realized, light efficiency can be improved, loss of red and green color is generated It is possible to improve the color reproduction rate.

Thus, the luminous efficiency and lifetime of the OLED (100 in FIG. 2) can be further improved.

In addition, in the embodiment of the present invention, the structure in which the organic electroluminescent diode (E in FIG. 3) is composed of two stacks (229a and 229b in FIG. 3) has been shown and described. However, in the organic electroluminescent diode 3E) may be made up of three stacks. 3 stack structure, it may further include a separate third light emitting layer. In this case, red light and green light emission characteristics may be separately formed.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

211: first electrode, 215: second electrode,
213: organic light emitting layers 221a and 221b: first and second hole transporting films 223a and 223b: first and second light emitting films 224a and 224b: first and second electron transporting)
229a, 229b: first and second stacks
E: Organic light emitting diode

Claims (11)

A first electrode comprising a reflective layer;
A first hole transport layer located above the first electrode;
A first luminescent layer located above the first hole transporting layer and emitting blue color;
A first electron transport film located above the first light emitting film;
A charge generation film located above the first electron transport film;
A second hole transport film located above the charge generation film;
A second light emitting film located on the second major transport film and emitting red and green colors;
A second electron transport film located on the second light emitting film;
A second electrode disposed on the second electron transport film,
Wherein the first light-emitting film and the second light-emitting film implement a micro cavity effect.
The method according to claim 1,
Wherein a distance between the first electrode and the second electrode is 200 to 400 nm.
The method according to claim 1,
The first electrode is formed of a double layer of the reflective layer and the transparent layer and the reflective layer is formed of one selected from the group consisting of aluminum (Al), tantalum (Ta), silver (Ag), aluminum alloy (AlNd) An organic light-emitting device comprising a material.
The method according to claim 1,
The second electrode may be formed of one material selected from aluminum (Al), aluminum alloy (AlNd), silver (Ag), magnesium (Mg), gold (Au), aluminum magnesium alloy (AlMg), and silver magnesium alloy And the metal material is thinly deposited.
The method according to claim 1,
Wherein a hole injection film is interposed between the first electrode and the first hole transporting film, and an electron injecting film is interposed between the second electrode and the second electron transporting film.
A first substrate on which driving thin film transistors are formed for R, G, and B subpixels;
And a second light-emitting film formed in the R, G, and B sub-pixels on the first substrate, the first light-emitting film emitting a blue color, and the second light-emitting film emitting red and green colors, An electroluminescent diode;
A first substrate, a second substrate,
Wherein the first light-emitting film and the second light-emitting film implement a micro cavity effect.
The method according to claim 6,
Wherein the organic light emitting diode comprises a first electrode including a reflective layer, a first hole transport film located on the first electrode, a first light emitting film located on the first hole transport film, A first electron transport film located above the light emitting film, a charge generation film located above the first electron transport film, a second hole transport film located above the charge generation film, A second electron transport film located above the second light emitting film, and a second electrode disposed on the second electron transport film and being translucent.
8. The method of claim 7,
Wherein the distance between the first and second electrodes is different for each of the R, G, and B sub-pixels.
8. The method of claim 7,
Wherein a distance between the first and second electrodes is the same in the R and G sub-pixels, and the B sub-pixel is different.
The method according to claim 6,
Wherein the R, G, and B subpixels include R, G, and B color filters, respectively, and the organic light emitting diode emits white light (W).
The method according to claim 6,
Wherein an adhesive layer is provided on the passivation layer, and the second substrate is bonded to the first substrate through the adhesive layer.

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