KR20170114059A - Organic light-emitting diode having emission layer comprising aligned liquid crystal molecules - Google Patents

Abstract

And a light emitting layer including aligned liquid crystal molecules. The organic light emitting diode of the present invention includes a substrate, a lower electrode disposed on the substrate, an alignment layer disposed on the lower electrode and having a first region oriented in a first direction and a second region oriented in a second direction, Wherein the organic molecules are aligned in a first direction on the first region and aligned in a second direction on the second region, and an organic light emitting layer arranged on the organic light emitting layer, wherein the organic molecules are electroluminescent liquid crystals, And an electrode. According to the present invention, a three-dimensional organic light emitting diode display can be realized without decreasing the light efficiency by providing the light emitting layer in which the electroluminescent liquid crystal molecules are aligned according to the alignment direction of the orientation film. Further, by using a? / 4 retarder, the left-handed circularly polarized light and the right-handed circularly polarized light can be simultaneously realized, and the effect of reducing the process cost can be achieved while maintaining the light efficiency.

Description

[0001] The present invention relates to an organic light emitting diode (OLED) having an emission layer including aligned liquid crystal molecules,

The present invention relates to a light emitting diode, and more particularly to an organic light emitting diode.

One of the key technologies of the information and communication age in recent years is the display which implements various information on the screen, which is thinner and lighter and can be carried at a high speed, while rapidly developing toward high performance quality. In particular, a light emitting display device using an organic light emitting diode (OLED) does not require a separate light source unlike a liquid crystal display (LCD), so that it can be manufactured with a lighter and thinner thickness, High luminance, low power consumption, and so on, and is attracting attention as a next generation display device of portable electronic devices.

The basic structure of a light emitting display using such an organic light emitting diode (OLED) is a structure in which a first electrode, an organic light emitting layer, and a second electrode are sequentially stacked, and electrons and holes are recombined in the organic light emitting layer, And the electroluminescent phenomenon in which the exciton emits light with energy emitted while transitioning to a low energy state is driven by the principle.

Meanwhile, a spatially multiplexed 3D display, which has been actively researched recently among displays, provides a plurality of viewpoint images at the same time, and displays the left and right images on one screen at a time and displays them on a physical device And reach the left eye and the right eye, respectively.

In a currently-developed three-dimensional display, a left-handed circularly polarized light and a right-handed circularly polarized light are produced based on a liquid crystal display. In this case, a polarizing plate is indispensably required, so that a light efficiency decreases and a cost increases.

Korean Patent Publication No. 10-2004-0111203

SUMMARY OF THE INVENTION It is an object of the present invention to provide a three-dimensional organic light emitting diode display having a light emitting layer capable of emitting polarized light at a desired position without a polarizing plate.

According to one aspect of the present invention, there is provided an organic light emitting diode. Wherein the organic light emitting diode comprises: a substrate; a lower electrode disposed on the substrate; an alignment layer disposed on the lower electrode and having a first region oriented in a first direction and a second region oriented in a second direction; Wherein the organic molecules are aligned in a first direction on the first region and aligned in a second direction on the second region, and an organic light emitting layer arranged on the organic light emitting layer, wherein the organic molecules are electroluminescent liquid crystals, Electrode.

The alignment layer may be an organic tunneling insulating layer.

The first direction may be +30 to +60, and the second direction may be -30 to -60.

The organic molecules may be PPV (poly (phenylene vinylene)) based organic molecules or PFO (polyfluorene) based organic molecules.

And a first charge conduction layer disposed between the lower electrode and the alignment layer.

And a second charge conduction layer disposed between the upper electrode and the organic light emitting layer.

And a? / 4 retarder disposed on the lower surface of the lower electrode.

According to the present invention, a three-dimensional organic light emitting diode display can be realized without decreasing the light efficiency by providing the light emitting layer in which the electroluminescent liquid crystal molecules are aligned according to the alignment direction of the orientation film.

Further, by using a? / 4 retarder, the left-handed circularly polarized light and the right-handed circularly polarized light can be simultaneously realized, and the effect of reducing the process cost can be achieved while maintaining the light efficiency.

The technical effects of the present invention are not limited to those mentioned above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the following description.

FIG. 1A is a cross-sectional view illustrating an organic light emitting diode display according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view of an organic light emitting diode display according to a first embodiment of the present invention, It is a perspective view.
2 is a cross-sectional view illustrating an organic light emitting diode display according to an exemplary embodiment of the present invention.
3 is a schematic diagram illustrating a phase delay by a? / 4 retarder according to an embodiment of the present invention.

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

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. Rather, the intention is not to limit the invention to the particular forms disclosed, but rather, the invention includes all modifications, equivalents and substitutions that are consistent with the spirit of the invention as defined by the claims. It will be appreciated that when an element such as a layer, region or substrate is referred to as being present on another element "on," it may be directly on the other element or there may be an intermediate element in between . Although the terms first, second, etc. may be used to describe various elements, components, regions, layers and / or regions, such elements, components, regions, layers and / And should not be limited by these terms.

FIG. 1A is a cross-sectional view illustrating an organic light emitting diode display according to a first embodiment of the present invention. FIG. 1B is a cross-sectional view of an organic light emitting diode display according to a first embodiment of the present invention, It is a perspective view.

Referring to FIGS. 1A and 1B, a substrate 100 may be provided. The substrate 100 may be a light-transmissive substrate as a flat plate member, in which case the substrate may be glass; Ceramics material; And may be made of a polymer material such as polycarbonate (PC), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polypropylene (PP) The substrate 100 includes a pair of adjacent unit pixel regions, specifically, a pair of red pixel regions R1 and R2, a pair of green pixel regions G1 and G2, and a pair of blue pixels And may have regions B1 and B2.

The lower electrode 200 may be positioned on the substrate 100. The first charge transfer layer 300, the alignment layer 400, the organic light emitting layer 500, the second charge transfer layer 600, and the upper electrode 700 may be sequentially disposed on the lower electrode 200.

The lower electrode 200 may be formed within each unit pixel region R1, R2, G1, G2, B1, and B2. A thin film transistor (not shown) electrically connected to the lower electrode 200 may be disposed between the lower electrode 200 and the substrate 100. In this case, the organic light emitting diode display may be an AMOLED (active matrix OLED) display. However, the present invention is not limited to this, and the lower electrode 200 may be formed in a line shape extending along the same color pixel regions adjacent to each other, and the upper electrode 700 may be formed of a plurality of lines orthogonal thereto, The intersection region of the lower electrode 200 and the upper electrode 700 may be defined as unit pixel regions. In this case, the organic light emitting diode display may be a passive matrix OLED (PMOLED) display.

The lower electrode 200 may be an anode or a cathode as a light-transmitting electrode. When the lower electrode 200 is an anode, the upper electrode 700 may be a cathode, and when the lower electrode 200 is a cathode, the upper electrode 700 may be an anode. The upper electrode 700 may be a light reflecting electrode or a light transmitting electrode. When the upper electrode 700 is a light transmitting electrode, a reflector (not shown) may be further disposed on the upper electrode 700.

The anode may be a transparent conductive metal oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), fluorine tin oxide (FTO), or Al-doped ZnO (AZO). The cathode may be formed of a metal such as aluminum, nickel, cobalt, platinum, silver, gold, copper, molybdenum, titanium or tantalum or an alloy containing them such that it is thin enough to transmit light (In the case of the upper electrode).

The first charge transport layer 300 may include a first charge injection layer 310 and a first charge transport layer 320. The second charge transport layer 600 may include a second charge injection layer 610 and a second charge transport layer 620.

For example, when the lower electrode 200 is an anode and the upper electrode 700 is a cathode, the first charge transport layer 300 may be a hole transport layer, and the first charge injection layer 310 may be a hole injection layer The first charge transport layer 320 may be a hole transport layer, the second charge transport layer 600 may be an electron transport layer, the second charge injection layer 610 may be an electron injection layer, 2 charge transport layer 620 may be an electron transport layer.

As another example, when the lower electrode 200 is a cathode and the upper electrode 700 is an anode, the first charge transport layer 300 may be an electron conduction layer, and the first charge injection layer 310 may be an electron injection layer The first charge transport layer 320 may be an electron transport layer, the second charge transport layer 600 may be a hole transport layer, the second charge injection layer 610 may be a hole injection layer, 2 charge transport layer 620 may be a hole transport layer.

The hole injecting layer may be a poly (3,4-ethylenedioxythiophene) (PEDOT: PSS) layer, and the hole transporting layer may be a NPD (N, N'-di (1-naphthyl) N, N'-diphenyl-N, N'-di (3-methylphenyl) -4,4'-diaminobiphenyl (TPD), and the electron transport layer may be a layer of tris (8-quinolinolate) (Alq3) layer, and the electron injection layer may be LiF, NaCl, CsF, Li2O, BaO, BaF2, or Liq (lithium quinolate). However, the present invention is not limited thereto, and known materials corresponding to each layer can be used.

The alignment layer 400 may be an organic tunneling insulating layer formed to have a thickness that is thin enough to tunnel the charge, for example, about 20 nm or less. In addition, the alignment layer 400 may be a horizontal alignment layer. The alignment layer 400 may be formed using poly-amic acid, polyimide, lecithin, nylon, or PVA (polyvinylalcohol). Further, the alignment film 400 can be oriented by a physical rubbing method, a photo alignment method, or a groove patterning method. Specifically, the alignment film 400 positioned within one of the pair of red pixel regions R1, one of the pair of green pixel regions G1, and one of the pair of blue pixel regions B1, (R2) of the pair of red pixel regions, the remaining one (G2) of the pair of green pixel regions, and the remaining one (B2) of the pair of blue pixel regions The alignment film 400 may be oriented in the second direction. The first direction and the second direction may mean an azimuth angle in one plane, and the first direction may be + 30 ° to + 60 °, for example, + 45 °, and the second direction may be -30 Deg.] To -60 [deg.], For example -45 [deg.].

The organic light emitting layer 500 may be a liquid crystal having optically anisotropic properties and a layer containing organic molecules capable of electroluminescence, that is, electroluminescent liquid crystals. As an example, the organic light emitting layer 500 may contain a PPV (poly (phenylene vinylene)) organic molecule or a PFO (polyfluorene) organic molecule. The red light emitting layer 500R having red light emitting organic molecules is formed in a pair of red pixel regions R 1 and R 2 by a pair of green pixel regions G 1 And G2 may include a green light emitting layer 500G having green light emitting organic molecules and a blue light emitting layer 500B having blue light emitting organic molecules in a pair of blue pixel regions B1 and B2.

On the other hand, the organic molecules may be aligned according to the alignment direction of the alignment layer 400. Specifically, organic molecules positioned within one of the pair of red pixel regions (R1), one of a pair of green pixel regions (G1), and one of a pair of blue pixel regions (B1) (R2) of the pair of red pixel regions, the remaining one (G2) of the pair of green pixel regions, and the remaining one (B2) of the pair of blue pixel regions The organic molecules may be aligned in the second direction. Accordingly, the same color light emitting layers 500R, 500G, and 500B may have a region having organic molecules aligned in the first direction and a region having organic molecules aligned in the second direction. In this case, as described above, the first direction and the second direction may mean an azimuth angle in one plane, and the first direction may be + 30 ° to + 60 °, for example, + 45 ° The second direction may be -30 [deg.] To -60 [deg.], For example -45 [deg.].

When power is connected between the lower electrode 200 and the upper electrode 700 of the organic light emitting diode, the first charge is conducted from the lower electrode 200 through the first charge transfer layer 300, A second charge may be conducted from the upper electrode 700 through the second charge transfer layer 600 and injected into the organic light emitting layer 500 by tunneling the light emitting layer 400 to the organic light emitting layer 500, . The first charge and the second charge are recombined in the organic light emitting layer 500 to form an exciton, and the exciton can emit light of a corresponding color while shifting to a low energy level. In this case, organic molecules arranged in the first direction in the organic light emitting layer 500 can emit linearly polarized light in the second direction from organic molecules in which linearly polarized light in the first direction is arranged in the second direction. As a result, it is possible to realize a 3D OLED display capable of emitting linearly polarized light at a desired position by only aligning the liquid crystal organic molecules without a separate polarizing plate.

FIG. 2 is a cross-sectional view illustrating an organic light emitting diode display according to a first embodiment of the present invention, and FIG. 3 is a schematic diagram illustrating a phase delay by a? / 4 retarder according to an embodiment of the present invention.

Referring to FIGS. 2 and 3, a λ / 4 retarder 10 may be disposed on the light extracting surface of the organic light emitting diode display described with reference to FIGS. 1A and 1B. As an example, the? / 4 retarder 10 may be disposed on the lower surface of the lower substrate 100 which is a light transmitting substrate. In this case, the linearly polarized light emitted from the light emitting layer 500 can be converted into circularly polarized light. In other words, light that is linearly polarized in the first direction and linearly polarized in the second direction emitted from the light emitting layer 500 can be converted into left-handed circularly polarized light and right-handed circularly polarized light, respectively.

Therefore, in the conventional 3D display, left-handed circularly polarized light and right-handed circularly polarized light are produced by using a film-type patterned retarder (FPR). In the present invention, liquid crystal organic molecules of the light emitting layer have different azimuth angles (E.g., + 45 °, -45 °), the left-handed circularly polarized light and the right-handed circularly polarized light can be formed only by the λ / 4 retarder. As a result, the 3D display can be realized at low cost without decreasing the light efficiency.

It should be noted that the embodiments of the present invention disclosed in the present specification and drawings are only illustrative of specific examples for the purpose of understanding and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention are possible in addition to the embodiments disclosed herein.

100: substrate 200: lower electrode
300: first charge transfer layer 310: first charge injection layer
320: second charge transporting layer 400: alignment film
500: organic light emitting layer 500R: red light emitting layer
500G: green light emitting layer 500B: blue light emitting layer
600: second charge conduction layer 610: second charge injection layer
620: second charge transport layer 700: upper electrode
10:? / 4 retarder R1, R2, G1, G2, B1, B2:

Claims (14)

Board;
A lower electrode positioned on the substrate;
An orientation layer disposed on the lower electrode and having a first region oriented in a first direction and a second region oriented in a second direction;
An organic light emitting layer disposed on the alignment layer and having organic molecules that are electroluminescent liquid crystals, the organic molecules being aligned in a first direction on the first region and aligned in a second direction on the second region; And
And an upper electrode disposed on the organic light emitting layer. The method according to claim 1,
Wherein the alignment layer is an organic tunneling insulation layer. The method according to claim 1,
Wherein the first direction is +30 [deg.] To + 60 [deg.] And the second direction is -30 [deg.] To -60 [deg.]. The method according to claim 1,
Wherein the organic molecules are PPV (poly (phenylene vinylene)) based organic molecules or PFO (polyfluorene) based organic molecules. The method according to claim 1,
And a first charge transporting layer disposed between the lower electrode and the alignment layer. The method according to claim 1,
And a second charge transport layer disposed between the upper electrode and the organic light emitting layer. The method according to claim 1,
/ 4 retarder disposed on the lower surface of the lower substrate (100). A substrate having a pair of red pixel regions, a pair of green pixel regions, and a pair of blue pixel regions;
A lower electrode positioned on the substrate;
A plurality of red pixel regions disposed on the lower electrode and having one of the pair of red pixel regions, one of the pair of green pixel regions, and one of the pair of blue pixel regions, And is arranged to be oriented in the second direction on the other of the pair of red pixel areas, the other one of the pair of green pixel areas, and the other one of the pair of blue pixel areas An oriented alignment film;
A red light emitting layer disposed on the pair of red pixel regions, a green light emitting layer disposed on the pair of green pixel regions, and a red light emitting layer disposed on the pair of blue pixel regions, An organic light emitting layer having organic light emitting layers, organic light emitting layers having blue light emitting layers, and organic molecules being electroluminescent liquid crystals aligned along the alignment direction of the alignment layer; And
And an upper electrode disposed on the organic light emitting layer. 9. The method of claim 8,
Wherein the alignment layer is an organic tunneling insulation layer. 9. The method of claim 8,
Wherein the first direction is +30 [deg.] To + 60 [deg.] And the second direction is -30 [deg.] To -60 [deg.]. 9. The method of claim 8,
Wherein the organic molecules are PPV (poly (phenylene vinylene)) based organic molecules or PFO (polyfluorene) based organic molecules. 9. The method of claim 8,
And a first charge transporting layer disposed between the lower electrode and the alignment layer. 9. The method of claim 8,
And a second charge transport layer disposed between the upper electrode and the organic light emitting layer. 9. The method of claim 8,
And a? / 4 retarder disposed on the lower surface of the lower electrode.

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