KR100708752B1 - Organic light emitting display device - Google Patents

Abstract

According to an exemplary embodiment of the present invention, an organic light emitting display apparatus having an improved light efficiency may include an intermediate layer including a first electrode, a second electrode facing the first electrode, and at least an emission layer interposed between the first electrode and the second electrode. And one of the first electrode and the second electrode has a plurality of cylindrical shell-like through parts.

Description

Organic light emitting display apparatus

1 is a perspective view schematically illustrating a first electrode included in an organic light emitting display device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating an organic light emitting display device having a first electrode illustrated in FIG. 1.

3 is a graph comparing light efficiency of an organic light emitting display device emitting red light having the structure shown in FIG. 2 with light efficiency of an organic light emitting display device according to a comparative example.

4 is a graph comparing light efficiency of the organic light emitting display device emitting green light having the structure shown in FIG. 2 with light efficiency of the organic light emitting display device according to the comparative example.

FIG. 5 is a graph comparing light efficiency of an organic light emitting display device emitting blue light having the structure shown in FIG. 2 with light efficiency of an organic light emitting display device according to a comparative example.

FIG. 6 is a cross-sectional view schematically illustrating an organic light emitting device included in an organic light emitting display device according to another exemplary embodiment.

7 is a schematic cross-sectional view of an organic light emitting display device according to another exemplary embodiment.

<Explanation of symbols for the main parts of the drawings>

100 substrate 130 organic light emitting device

131: first electrode 133: intermediate layer

1331: hole injection layer 1332: hole transport layer

1333: light emitting layer 1334: electron transport layer

1335: electron injection layer 134; Second electrode

The present invention relates to an organic light emitting display device, and more particularly, to an organic light emitting display device with improved light efficiency.

An organic light emitting display device is a display device having a pixel having an organic light emitting element, and has attracted attention as a next generation display device because of its advantages of having a wide viewing angle, excellent contrast, and fast response speed.

A recent demand for such an organic light emitting display device is to achieve high light efficiency even at low power. Various attempts have been made for this.

Among these attempts, the method of raising the supply voltage makes it possible to achieve the intended brightness enhancement but contrary to the lightening accompanied by the increase in the capacity of the battery, and also reduces the lifespan of the battery and the self-light emitting device. For this reason, the prior art has been proposed to improve the luminance while lowering the supply voltage.

Japanese Laid-Open Patent Publication No. 4-192290 discloses an inorganic EL device in which a plurality of microlenses for condensing having a size equal to or larger than that of the inorganic EL element are provided on the outer surface of the transparent substrate on which the inorganic EL element is formed. . The direction of exiting the light is directed in a predetermined direction to increase the luminance in that direction. However, since the EL element is a surface light source, when a microlens having a size equal to or larger than that of the EL element is used, EL light is inevitably collected, but rather diffused, and due to overlapping with images by adjacent EL elements. There was a problem that the sharpness of the image is lowered.

The present invention has been made to solve various problems including the above problems, and an object of the present invention is to provide an organic light emitting display device with improved light efficiency.

According to an aspect of the present invention, there is provided an intermediate layer including a first electrode, a second electrode facing the first electrode, and at least an emission layer interposed between the first electrode and the second electrode. One of the second electrodes provides an organic light emitting display device having a plurality of cylindrical shell-like through parts.

According to another aspect of the present invention, a substrate may be further provided, and a plurality of cylindrical shell-like through portions may be provided at an electrode having a shorter distance from the substrate among the first electrode and the second electrode. have.

According to another feature of the invention, the electrode provided with a plurality of cylindrical shell-shaped through portions may be provided with a transparent or translucent material.

According to another feature of the invention, the light generated in the intermediate layer may be taken out through the electrode provided with a plurality of cylindrical shell-shaped through-holes.

According to still another feature of the present invention, an electrode in which the plurality of cylindrical shell-like through portions of the first electrode and the second electrode is not provided may be formed of a reflective material.

According to another feature of the invention, the through parts may be filled with the material for forming the intermediate layer.

According to another feature of the invention, the through portions may be filled with porous silica, silicon oxide or silicon nitride.

The present invention also provides a first electrode having a plurality of cylindrical shell-shaped through portions, a second electrode facing the first electrode and having a plurality of cylindrical shell-shaped through portions, the first electrode and the second electrode. An organic light emitting display device comprising an intermediate layer including at least a light emitting layer interposed between electrodes.

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

1 is a perspective view schematically illustrating a first electrode included in an organic light emitting display device according to an embodiment of the present invention, and FIG. 2 is a schematic view of an organic light emitting display device having a first electrode illustrated in FIG. 1. It is sectional drawing.

1 and 2, an organic light emitting device 130 included in an organic light emitting display device according to an exemplary embodiment of the present invention may include a first electrode 131 and a second electrode facing the first electrode 131. An electrode 134 and an intermediate layer 133 interposed between the first electrode 131 and the second electrode 134 are provided. The intermediate layer 133 interposed between the first electrode 131 and the second electrode 134 includes at least a light emitting layer 1333.

The first electrode 131 functions as an anode electrode, and the second electrode 134 functions as a cathode electrode. Of course, various modifications are possible, such that the first electrode 131 functions as a cathode electrode and the second electrode 134 may function as an anode electrode.

The first electrode 131 may be made of a transparent material or a translucent material. That is, the organic light emitting display device according to the present embodiment is an organic light emitting display device in which light generated in the light emitting layer 1333 included in the intermediate layer 133 is extracted to the outside through the first electrode 131. The first electrode 131 may be formed of ITO, IZO, ZnO, In ₂ O ₃ , or the like. Of course, in some cases, a structure having a layer made of Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and compounds thereof, and a layer formed of a material such as ITO, IZO, ZnO, or In ₂ O ₃ can be taken. Of course, various modifications are possible.

The second electrode 134 may be made of a transparent material or a reflective material. That is, when the light generated from the light emitting layer 1333 included in the intermediate layer 133 is extracted to the outside only through the first electrode 131, the light proceeds toward the second electrode 134 of the light generated from the light emitting layer 1333. When the light is reflected from the second electrode 134 to be extracted to the outside through the first electrode 131, the second electrode 134 is formed of a reflective material. However, when the light emitted from the light emitting layer 1333 proceeds toward the second electrode 134 to be extracted to the outside through the second electrode 134, that is, to implement a double-sided light emitting display device, The second electrode 134 may also be provided with a transparent material or a translucent material.

When the second electrode 134 is provided as a transparent or translucent electrode, a layer made of Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and a compound thereof, and ITO, IZO, ZnO, or In ₂ O ₃ It is possible to take a structure having a layer formed of such a material. When the second electrode 134 is provided as a reflective electrode, it may have a structure formed by depositing Li, Ca, LiF / Ca, LiF / Al, Al, Mg, and compounds thereof on the entire surface.

The intermediate layer 133 interposed between the first electrode 131 and the second electrode 134 includes at least the light emitting layer 1333 as described above, but may also include various layers. The intermediate layer 133 may be provided with a low molecular weight or high molecular organic material.

When using a low molecular weight organic material, as shown in FIG. 2, a hole injection layer (HIL: hole injection layer, 1331), a hole transport layer (HTL: hole transport layer, 1332), an emission layer (EML: emissive layer, 1333), an electron transport layer (ETL: electron transport layer, 1334) or electron injection layer (EIL: electron injection layer, 1335) and the like, and the usable organic materials may also be copper phthalocyanine (CuPc: copper phthalocyanine), N, N-di (naphthalene -1-yl) -N, N'-diphenyl-benzidine (N, N'-Di (naphthalene-1-yl) -N, N'-diphenyl-benzidine: NPB), tris-8-hydroxyquinoline aluminum It can be applied in various ways, including (tris-8-hydroxyquinoline aluminum) (Alq3). These low molecular weight organic materials may be formed by a method such as vacuum deposition using masks.

In the case of using a polymer organic material, it may have a structure generally provided with a hole transport layer (HTL) and a light emitting layer (EML), in which case, PEDOT is used as the hole transport layer, and poly-phenylenevinylene (PPV) and polyfluorene are used as the light emitting layer. Polymer organic materials such as (Polyfluorene) can be used.

As described above, a recent demand for an organic light emitting display device is to achieve high light efficiency even at low power. To this end, in the organic light emitting diode display according to the present exemplary embodiment, a plurality of through parts 131a are provided on the first electrode 131. The penetrating portion 131a is a penetrating portion in the form of a cylindrical shell. By taking such a structure, the ratio of the light emitted from the light emitting layer 1333 included in the intermediate layer 133 to the outside through the first electrode 131 can be increased, thereby increasing the organic consumption without increasing the power consumption. The luminance at the front of the light emitting display device can be improved.

Of course, the first electrode 131 may be provided with a cylindrical through portion instead of the cylindrical shell through portion 131a. However, when the cylindrical shell-shaped penetrating portion is provided rather than the cylindrical penetrating portion, the luminance at the front side of the organic light emitting display device is significantly improved under the same conditions.

Table 1 is a table comparing the light efficiency of the organic light emitting display device emitting red light having the structure shown in FIG. 2 and the light efficiency of the organic light emitting display device according to the comparative example, Figure 3 is a graph showing this. That is, Table 1 below is a table comparing the transmittance when the first electrode 131 is provided with a cylindrical shell through portion 131a and the transmittance when the first electrode is provided with a cylindrical through portion, 3 is a graph showing this. The results of Table 1 and the graph of FIG. 3 show a case where the wavelength of the light generated in the light emitting layer is 610 nm to 630 nm, and the cylindrical shell through portion and the cylindrical through portion have a period of 600 nm. At this time, in the case of the cylindrical shell through portion, the outer radius of the through portion was 100 nm and the inner radius was 50 nm, and the cylindrical through portion had a radius of 100 nm.

Wavelength (μm) Cylindrical shell shape Cylindrical shape Transmittance ratio (%) 0.610 0.711322401 0.653953948 108.7725525 0.611 0.706117298 0.602918359 117.1165695 0.612 0.695879901 0.527944010 131.8094131 0.613 0.676698491 0.448116094 151.0096380 0.614 0.642856034 0.404430162 158.9535337 0.615 0.590726776 0.410821602 143.7915567 0.616 0.532040766 0.443215268 120.0411636 0.617 0.498329022 0.478764041 104.0865603 0.618 0.503853535 0.508642472 99.05848663 0.619 0.530552530 0.531507250 99.82037492 0.620 0.559828523 0.548244883 102.1128588 0.621 0.584664278 0.560014456 104.4016402 0.622 0.604208721 0.567734860 106.4244532 0.623 0.619351054 0.572019478 108.2744693 0.624 0.631148119 0.573220351 110.1056720 0.625 0.640451117 0.571491626 112.0665794 0.626 0.647880438 0.566865062 114.2918274 0.627 0.653874386 0.559367185 116.8953781 0.628 0.658739673 0.549239528 119.9366833 0.629 0.662689651 0.537348064 123.3259587 0.630 0.665870679 0.525809679 126.6372045

Referring to the graphs of Table 1 and FIG. 3, the light generated from the light emitting layer 1333 is extracted to the outside when the cylindrical electrode-shaped penetrating portion is provided in the first electrode 131. It can be seen that the amount is larger. This is because there is no cut-off of the wavelength of light passing through the cylindrical shell-shaped through portion than the cylindrical through portion, and thus the transmission amount is significantly increased.

Table 2 is a table comparing the light efficiency of the organic light emitting display device emitting green light having the structure shown in FIG. 2 and the light efficiency of the organic light emitting display device according to the comparative example, Figure 4 is a graph showing this. That is, Table 2 below is a table comparing the transmittance when the first electrode 131 is provided with a cylindrical shell through portion 131a and the transmittance when the first electrode is provided with a cylindrical through portion, 4 is a graph showing this. The results of Table 2 and the graph of FIG. 4 show a case where the wavelength of the light generated in the light emitting layer is 520 nm to 540 nm, and the cylindrical shell through portion and the cylindrical through portion have a period of 600 nm. At this time, in the case of the cylindrical shell through portion, the outer radius of the through portion was 100 nm and the inner radius was 50 nm, and the cylindrical through portion had a radius of 100 nm.

Wavelength (μm) Cylindrical shell shape Cylindrical shape Transmittance ratio (%) 0.520 0.655181443 0.348984511 187.7394044 0.521 0.661364882 0.349675440 189.136784 0.522 0.666432839 0.350356883 190.2154264 0.523 0.670503930 0.351027044 191.0120434 0.524 0.673712655 0.351684356 191.567422 0.525 0.676189534 0.352327473 191.9207517 0.526 0.678052239 0.352955260 192.1071354 0.527 0.679402723 0.353566783 192.1568303 0.528 0.680327372 0.354161296 192.0953475 0.529 0.680898466 0.354738226 191.9439226 0.530 0.681176091 0.355297158 191.7201072 0.531 0.681210068 0.355837822 191.4383539 0.532 0.681041693 0.356360077 191.1105469 0.533 0.680705249 0.356863901 190.7464574 0.534 0.680229266 0.357349370 190.3541248 0.535 0.679637566 0.357816653 189.9401721 0.536 0.678950108 0.358265994 189.5100625 0.537 0.678183683 0.358697704 189.0683088 0.538 0.677352471 0.359112152 188.6186439 0.539 0.676468496 0.359509750 188.1641585 0.540 0.675541997 0.359890951 187.7074137

Referring to the graphs of Table 2 and FIG. 3, even when the light generated from the light emitting layer 1333 is green light, the cylindrical electrode penetrating part is provided than the case where the cylindrical penetrating part is provided in the first electrode 131. In this case, it can be seen that the amount of light emitted from the light emitting layer 1333 is extracted to the outside. This is because there is no cut-off of the wavelength of light passing through the cylindrical shell-shaped through portion than the cylindrical through portion, and thus the transmission amount is significantly increased. In particular, in this case, it can be seen that when the cylindrical shell-shaped penetrating portion is provided for almost all wavelength bands, the transmittance is nearly twice that of the cylindrical penetrating portion.

Table 3 is a table comparing the light efficiency of the organic light emitting display device emitting blue light with the structure shown in FIG. 2 and the light efficiency of the organic light emitting display device according to the comparative example, Figure 5 is a graph showing this. That is, Table 3 below is a table comparing the transmittance when the first electrode 131 is provided with a cylindrical shell through portion 131a, and the transmittance when the first electrode is provided with a cylindrical through portion, 5 is a graph showing this. The result of Table 3 and the graph of FIG. 5 show a case where the wavelength of light generated in the light emitting layer is 460 nm to 479 nm, and the cylindrical shell through portion and the cylindrical through portion have a period of 600 nm. At this time, in the case of the cylindrical shell through portion, the outer radius of the through portion was 100 nm and the inner radius was 50 nm, and the cylindrical through portion had a radius of 100 nm.

Wavelength (μm) Cylindrical shell shape Cylindrical shape Transmittance ratio (%) 0.460 0.732356841 0.634581655 115.4078178 0.461 0.732312649 0.631437508 115.9754750 0.462 0.731802651 0.627784220 116.5691376 0.463 0.730743074 0.623733292 117.1563365 0.464 0.729035041 0.619551908 117.6713414 0.465 0.726569202 0.615764435 117.9946683 0.466 0.723243521 0.613266129 117.9330614 0.467 0.719011921 0.613363734 117.2243942 0.468 0.713998519 0.617557600 115.6165058 0.469 0.708728741 0.626884072 113.0557902 0.470 0.704489602 0.641019561 109.9014204 0.471 0.703572787 0.657960792 106.9323273 0.472 0.708606302 0.674885476 104.9965256 0.473 0.720406259 0.689516514 104.4799137 0.474 0.736356617 0.700812222 105.0718858 0.475 0.752196308 0.708769039 106.1271398 0.476 0.765096849 0.713901866 107.1711514 0.477 0.774410811 0.716844845 108.0304638 0.478 0.780678115 0.718159753 108.7053558 0.479 0.784704572 0.718281350 109.2475214

Referring to the graphs of Tables 3 and 5, even when the light emitted from the light emitting layer 1333 is blue light, the cylindrical electrode-shaped penetrating part is provided than the case where the cylindrical electrode is provided in the first electrode 131. In this case, it can be seen that the amount of light emitted from the light emitting layer 1333 is extracted to the outside. This is because there is no cut-off of the wavelength of light passing through the cylindrical shell-shaped through portion than the cylindrical through portion, and thus the transmission amount is significantly increased.

As such, the cylindrical electrode-like through portion 131a is provided on the first electrode 131, so that the first electrode 131 can be efficiently extracted to the outside of the light generated by the light emitting layer 1333 included in the intermediate layer 133. An organic light emitting display device having low power consumption and improved luminance at the front surface may be implemented. The cylindrical shell-like through portion 131a can be easily formed through an e-beam or the like.

1 and 2, when the cylindrical shell-like through portion 131a is provided in the first electrode 131, the inside of the through portion 131a may be filled with a material for forming the intermediate layer 133. have. 1 and 2, when forming the hole injection layer 1331, the cylindrical shell-shaped through part 131a may be filled with a material for forming the hole injection layer 1331.

FIG. 6 is a cross-sectional view schematically illustrating an organic light emitting device included in an organic light emitting display device according to another exemplary embodiment.

The organic light emitting device according to the present embodiment differs from the organic light emitting device according to the above embodiment in that the material filling the cylindrical shell-shaped through part 131a is different. As described above with reference to FIG. 2, when the cylindrical shell-shaped through part 131a is provided in the first electrode 131, the inside of the through part 131a may be filled with a material for forming the intermediate layer 133. Alternatively, the through part 131a may be filled with another material as shown in FIG. 6, for example, may be filled with porous silica, silicon oxide, or silicon nitride. This material is a material having a refractive index different from that of the material forming the first electrode 131, and it is easy for light generated in the light emitting layer 1333 to be extracted to the outside through the first electrode 131. Experimentally, by filling the through part 131a with a material having a refractive index lower than that of the first electrode 131, the effect could be further maximized.

7 is a schematic cross-sectional view of an organic light emitting display device according to another exemplary embodiment.

In the organic light emitting diode display according to the above-described embodiment, only the structure of the organic light emitting diode is disclosed. As shown in FIG. 7, at least one thin film transistor TFT is electrically connected to each pixel. In the case of the present invention can be applied.

Each pixel or subpixel has at least one organic thin film transistor (TFT) as seen in FIG. Referring to FIG. 7, a buffer layer (not shown) may be formed of SiO ₂ on the substrate 100 as necessary, and a thin film transistor TFT may be provided on the substrate 100. 7 illustrates a thin film transistor having an exemplary structure, and a thin film transistor having various other structures may be provided.

The passivation film 128 made of SiO ₂ or the like is formed on the thin film transistor TFT including the gate electrode 121, the source electrode and the drain electrode 123, the semiconductor layer 127, and the gate insulating layer 125. Is formed, and a pixel definition film 129 made of acryl, polyimide, or the like is formed on the passivation film 128. The passivation film 128 may serve as a protective film for protecting the thin film transistor and may serve as a planarization film for planarizing an upper surface thereof.

Although not shown in the drawings, at least one capacitor may be connected to the thin film transistor. The circuit including the thin film transistor is not necessarily limited to the example illustrated in FIG. 7, and may be variously modified.

Meanwhile, the organic light emitting element 130 having the same structure as described above is connected to any one of the source electrode and the drain electrode 123.

Meanwhile, although the intermediate layer 133 is shown to be patterned so as to correspond only to the subpixels in FIG. 7, this is illustrated for convenience of description of the configuration of the subpixels, and the intermediate layer 133 is integral with the intermediate layer of the adjacent subpixels. Of course, it may be formed as. In addition, some layers of the intermediate layer 133 may be formed for each subpixel, and other layers may be integrally formed with an intermediate layer of an adjacent subpixel.

The first electrode 131 may be patterned to correspond to each pixel or subpixel, and the second electrode 134 may be integrally formed in a plurality of pixels or subpixels.

The organic light emitting element formed on the substrate 100 is sealed by an opposing member (not shown). The opposing member may be formed of a glass or plastic material in the same manner as the substrate 100. In addition, the opposing member may be formed of a metal cap or the like.

In such an organic light emitting display device, since the first electrode 131 has the structure as described above, an organic light emitting display device with low power consumption and high luminance can be realized.

Meanwhile, although only the first electrode 131 has disclosed a structure having a cylindrical shell-like through portion, light generated in the light emitting layer 1333 passes through both the first electrode 131 and the second electrode 134 in both directions. In the case of the double-sided light emitting type and the like, both the first electrode 131 and the second electrode 134 may have such a structure.

In addition, in the above embodiments and modified examples, the first electrode 131 has a cylindrical shell-shaped through portion 131a, and the distance from the substrate 100 to the first electrode 131 is the substrate 100. Only the structure in which the first electrode 131 is disposed below the distance from the distance from the second electrode 134 to the second electrode 134 is disclosed. However, it is obvious that various modifications are possible, such that only the electrode disposed on the upper portion of which the distance from the substrate is relatively far may have such a structure. Of course, if the electrode is provided with an intermediate layer formed of an organic material prior to forming such a through portion, the intermediate layer may be damaged during the formation of the through portion. If the intermediate layer is formed after forming the through part of the same structure, damage to the intermediate layer may be prevented, but the present invention is not necessarily limited thereto.

According to the organic light emitting display device of the present invention made as described above, it is possible to implement an organic light emitting display device with further improved light efficiency.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (8)

A first electrode; A second electrode facing the first electrode; And And an intermediate layer including at least an emission layer interposed between the first electrode and the second electrode. Any one of the first electrode and the second electrode has a plurality of cylindrical shell-shaped through-holes. The method of claim 1, An organic light emitting display device further comprising a substrate, wherein a plurality of cylindrical shell-like through portions are provided at an electrode having a shorter distance from the substrate among the first electrode and the second electrode. The method of claim 1, An organic light emitting display device, characterized in that the electrode provided with a plurality of cylindrical shell-shaped through parts is made of a transparent or translucent material. The method of claim 1, The light emitted from the intermediate layer is emitted to the outside through an electrode provided with a plurality of cylindrical shell-shaped through-holes. The method of claim 1, The electrode of the first electrode and the second electrode of which the plurality of cylindrical shell-shaped through-holes are not provided is made of a reflective material. The method of claim 1, And the through parts are filled with the material for forming the intermediate layer. The method of claim 1, And the through parts are filled with porous silica, silicon oxide, or silicon nitride. A first electrode having a plurality of cylindrical shell-shaped through portions; A second electrode facing the first electrode and having a plurality of cylindrical shell-like through parts; And And an intermediate layer including at least an emission layer interposed between the first electrode and the second electrode.

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