TW201403906A - Organic light-emitting element and manufacturing method thereof - Google Patents

Abstract

The present invention provides an organic light-emitting element and a manufacturing method thereof. The organic light-emitting element includes a gate electrode, a dielectric layer disposed on the gate electrode, an active layer disposed on the dielectric layer, the active layer having a source region located at an edge of the active layer, a drain region located at a center of the active layer, and a channel region between the source region and the drain region, an organic light-emitting layer disposed on the drain region, a drain electrode disposed above the organic light-emitting layer, and a source electrode disposed on the source region.

Description

Organic light emitting element and method of manufacturing organic light emitting element

The present invention relates to an element for integrating an OLED (Organic Light-Emitting Diode) and an OTFT (Organic Thin Film Transistor).

OTFT and OLED are two major technology branches in the field of organic electronics. OLED has been used in the fields of display and illumination. OTFT has unique characteristics as a switching element and will likely replace the general inorganic TFT. OTFT has both electrical and optical properties as well as a variety of unique physical properties, and can be prepared in a relatively inexpensive process, such as a printing process, a coating process, etc., and can be prepared in a large area. Moreover, organic semiconductors have excellent flexibility and are the best compatible soft substrates. Therefore, OTFT and OLED will become the best candidate technologies for the next generation of soft electronic products.

In the existing AMOLED (Active Matrix/Organic Light-emitting Diode) display technology, a TFT active array is required to drive the OLED to emit light and turn off, and each OLED element needs to be connected to the TFT as a driving. Component The current required to illuminate the OLED. In the process of construction, it is necessary to construct a TFT array on a glass substrate, and then prepare an OLED light-emitting element, and the manufacturing process is complicated. The production cost is high and the pixel density is difficult to further increase.

In view of the above problems and/or other problems of the prior art, the present invention provides an organic light emitting element and a method of fabricating the organic light emitting element.

An organic light-emitting element provided by the present invention comprises: a gate electrode; an insulating layer disposed on the gate electrode; and an active layer disposed on the insulating layer, the active layer including a source region at an outer circumference thereof and a buffer region at a central portion thereof And a channel region between the source region and the germanium region; an organic light-emitting layer on the germanium region; and a germanium electrode on the organic light-emitting layer; and a source electrode located in the source region.

The method for manufacturing an organic light emitting device provided by the present invention comprises: forming a gate electrode on a substrate; forming an insulating layer on the gate electrode; forming an active layer on the insulating layer, the active layer including a source region located at an outer periphery thereof a crotch region of the central portion, and a channel region between the source region and the crotch region; forming a source electrode in the source region; An organic light-emitting layer is formed on the germanium region; a germanium electrode is formed on the light-emitting layer.

The invention integrates the organic light emitting diode and the thin film transistor, can integrate the switching element and the light emitting element, increases the aperture ratio, is beneficial to improve the contrast of the display device, has simple manufacturing process, low production cost, and can A better compatible soft substrate has high application value.

1‧‧‧Substrate

2‧‧‧ gate electrode

3‧‧‧Insulation

4‧‧‧ active layer

5‧‧‧ source electrode

5a‧‧‧ source area

6‧‧‧汲 structure

6a‧‧‧汲区

61‧‧‧Lighting layer

62‧‧‧Electronic transport layer

63‧‧‧Electronic injection layer

64‧‧‧汲 electrode

7a‧‧‧Channel area

1a is a schematic cross-sectional view of an organic light emitting device according to an embodiment of the present invention; FIG. 1b is a schematic cross-sectional view of an organic light emitting device according to another embodiment of the present invention; and FIG. 2 is an organic light emitting device of FIG. 1a. The top view; and Figure 3 shows the working diagram of the overall component.

Example embodiments will now be described more fully with reference to the drawings. However, the example embodiments can be embodied in a variety of forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be Those skilled in the art. In the figures, the thickness of the regions and layers are exaggerated for clarity. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are set forth However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be implemented without one or more of the specific details, or other methods, elements, materials, and the like may be employed. In other instances, well-known structures, materials or operations are not shown or described in detail to avoid obscuring aspects of the present disclosure.

The invention integrates an OTFT and an OLED on one component, and realizes TFT current driving OLED illumination on a single component.

1a is a cross-sectional view of an integrated component in accordance with an embodiment of the present invention, and FIG. 2 is a top plan view of the integrated component. The integrated component according to this example embodiment will be described below with reference to FIGS. 1a and 2.

The integrated component according to example embodiments includes a substrate 1, a gate electrode 2 disposed on the substrate 1, an insulating layer 3 disposed on the gate electrode 2, an active layer 4 disposed on the insulating layer 3, and an active layer 4 disposed on the active layer 4. a source electrode 5, an emission layer 61 disposed on the active layer 4 and located between the two source electrodes 5, an electron transport layer (ETL) 62, an electron injection layer (EIL; electron) Injection layer 63 and germanium electrode 64.

The substrate 1 may be a glass substrate or a flexible substrate.

The material of the gate electrode 2 may be, but not limited to, Indium Tin Oxides (ITO), and metal materials such as Al, Mo, and Ag. Or a material such as graphene.

The insulating layer 3 may be an inorganic insulating layer including one or more of SiO ₂ , SiN _x , and Al ₂ O ₃ , or may include polyvinyl alcohol (PVA), poly(methylmethacrylate). ; an organic insulating layer of one or more of PMMA), polystyrene (PS), polyvinylpyrrolidone (PVP), or a laminate structure comprising at least two inorganic insulating layers, or at least two A laminated structure of an organic insulating layer, or a laminated structure including at least one inorganic insulating layer and at least one organic insulating layer.

The active layer 4 is, for example, a p-type organic semiconductor layer, while the active layer 4 serves as a hole transport layer (HTL) of the OLED.

The active layer 4 may be, for example, an organic small molecule layer formed of an organic small molecule material or an organic small molecule doping material, or an organic polymer layer formed of an organic polymer material or an organic polymer doped material, or at least A laminate structure formed by two layers of organic small molecule layers, or a laminate structure formed of at least two organic polymer layers, or a laminate structure formed of at least one organic small molecule layer and at least one organic polymer layer.

The active layer 4 includes at least a crotch region 6a located at a central portion of the active layer 4, a channel region 7a located at the periphery of the crotch region 6a and located between the crotch region 6a and the source region 5a, and the source region 5a is disposed at The periphery of the channel region 7a is used to form the source electrode 5, and the source electrode 5 is connected to the active layer 4. The arrangement of the source electrode 5 can be used in the following two ways: as shown in FIG. 1a, the source electrode 5 can be disposed at On the active layer 4; or as shown in Figure 1b, The source electrode 5 may also be disposed on the periphery of the active layer 4.

In an embodiment of the present invention, the source region 5a, the crotch region 6a, and the channel region 7a may have a square shape as shown in Fig. 2, but the present invention is not limited thereto.

The source electrode 5 is located in the source region 5a. An emission layer (EML) 61, an electron transport layer (ETL) 62, an electron injection layer (EIL) 63, and a germanium electrode 64 are stacked on the germanium region 6a. The ruthenium electrode 64 also serves as a cathode layer of the OLED.

The material of the light-emitting layer 61 may be selected from: ADN, TCTA, BCP, CBP, dopant: FIrpic, Ir (MDQ) 2 (acac), Ir (ppy) 3, C545, Bcvbi, TBPe, etc.; material of the electron transport layer 62 It can be selected from: Alq3, TPBi, Bphen, LiQ, etc.; the material of the electron injection layer 63 can be selected from LiF; the material of the hole transport layer can be selected from: NPB, TPD, F4TCNQ, CuPc, pentacene and MTDATA; (HIL; hole injection layer) materials can be selected: MoO3, WO3, CFx, CuPc and F4TCNQ.

The source electrode 5 may be, for example, a metal layer formed of at least one of Au, Mg, Ca, Ag, Al, and Cu. The source electrode 5 may also be a laminated structure including two or more metal layers. If the active layer is a P-type semiconductor material, the source electrode 5 is a single metal material or alloy having a work function higher than 4.3 eV; if the active layer is an N-type semiconductor material, the source electrode 5 is selected from a metal material having a work function lower than 4.3 eV. Or alloy.

The ruthenium electrode 64 may be formed of, for example, a metal material, including Al, Ag, Mg, Ca, Mg, or an Ag alloy.

The above describes an organic light-emitting element according to an embodiment of the present disclosure. The structure of the piece, but the disclosure is not limited thereto. For example, the active layer 4 can be an N-channel active layer, and other layers can be set accordingly. The other layers may be correspondingly arranged to sequentially arrange the EML, HTL, HIL and metal anode on the N-type active layer.

In addition, the bottom gate structure has been described above, but the present disclosure is not limited thereto. For example, the present disclosure is also applicable to a top gate structure.

The organic light emitting elements according to the present disclosure may be bottom light emitting, top light emitting, and bidirectional light emitting structures. The direction of illumination depends on whether the gate electrode and the cathode are transparent.

The principle of operation of the integrated component according to an example embodiment of the present disclosure is described below with reference to FIG.

Referring to FIG. 3, the element according to the example embodiment is subjected to a negative bias when the energization operation is performed, the source electrode 5 is applied with a forward bias, and the xenon electrode (cathode) 64 is applied with a negative bias. Thus, the germanium electrode (OLED cathode) 64 injects electrons into the light-emitting layer 61 through the electron injecting layer 63 and the electron transporting layer 62. The source electrode 5 is injected into the hole and enters the light-emitting layer 61 via the active layer 4 (ie, the hole transport layer). Electrons and holes recombine at the luminescent layer 61 to emit light. The voltage of the gate electrode 2 controls the turn-on and turn-off of the integrated component, and regulates the carrier concentration of the active layer 4 (similar to the function of the gate capacitance of the TFT) through the gate voltage and the gate capacitance. For example, when the gate electrode 2 is not applied with a voltage or the applied voltage is positive, the integrated component is turned off.

A method of manufacturing an integrated component according to example embodiments is described below.

First, magnetron sputtering is performed on the glass substrate or the flexible substrate 1. The gate electrode 2 is formed by a method such as vapor deposition. The material of the gate electrode 2 may be, but not limited to, indium tin metal oxide (ITO), and a metal material such as Al, Mo, Ag, or the like.

Then, a gate insulating layer 3 is formed on the gate electrode 2. The gate insulating layer 3 may be an inorganic insulating layer constructed of SiO ₂ , SiN _x , Al ₂ O ₃ or the like, or an organic polymer insulating layer. The gate insulating layer 3 may have a single layer or a multilayer structure. When the insulating layer 3 is an inorganic material, it can be formed by, for example, a PECVD (Plasma Enhanced Chemical Vapor Deposition) process. When the insulating layer 3 is an organic polymer, it can also be formed by, for example, a spin coating process.

Then, an organic semiconductor material is formed on the gate insulating layer 3 to form the active layer 4. The active layer 4 serves as both an HTL (Hole Transport Layer) layer of the OLED and an active layer of the OTFT. For example, the active layer 4 can be fabricated using a P-type organic semiconductor material to form a P-channel active layer. The active layer 4 can be formed by processes such as evaporation, coating, and printing.

The source electrode 5 is formed on the periphery of the active layer 4 by, for example, evaporation or printing. A drain structure 6 is formed on the central portion of the active layer 4. The drain structure 6 includes a light-emitting layer 61, an electron transport layer 62, an electron injection layer 63, and a germanium electrode 64 in this order on the active layer 4. The germanium electrode 64 also serves as the cathode of the OLED. The drain structure 6 can be formed by an evaporation process using a mask or a printing/printing process or the like.

The structure and working principle of the organic light-emitting element of the present invention are described above by taking FIG. 2 as an example. In the organic light-emitting element of the case The active layer 4 may also be an N-type organic semiconductor layer. The OLED portion of the type of organic light-emitting element is an inverted structure compared to the element shown in FIG. 2, and the active layer 4 serves as an electron transport layer of the OLED. (ETL: electron transport layer), an EML, an HTL, a hole injection layer (HIL), and a metal anode layer are sequentially formed above the active layer 4. When energized, the gate electrode applies a forward bias, the source electrode applies a negative bias, and the anode (drain) applies a forward bias. The OLED anode is thus injected into the hole and enters the EML via the HIL and HTL. The source electrode injects electrons into the EML via the ETL (ie, active layer 4). The electrons and holes are combined at the EML to emit light.

The invention realizes integration of OLED and OTFT on one component. Since the driving TFT and the OLED are integrated on one component, the space can be reduced and the aperture ratio can be increased. For example, in an AMOLED (Active Matrix Organic Light-emitting Diode) display panel, in order to achieve a higher aperture ratio, it is always necessary to reduce the area occupied by the TFT in one pixel, and increase Large OLED area, thereby increasing the displayable area. The structure selected for the present invention not only integrates the TFT and the OLED on one element, but also reduces the area occupied by one electrode of the TFT. Moreover, the area of this portion is shared with the OLED light-emitting region, that is, it can be understood that the area of the TFT is shared for use by the OLED, and the aperture ratio of the display pixel can be remarkably improved.

For a conventional TFT, if this structure is designed, although the width of the effective channel can be increased to increase the gate current ID, the area used for the TFT is increased, and the aperture ratio is sacrificed. The invention The integrated components can combine both, increasing the channel width, increasing the drive current, and increasing the aperture ratio.

Further, the present invention designs the source region, the germanium region, and the channel region to be surrounded. In this configuration, the channel region surrounds the crotch region, and the drive current can be maximized, thereby maximizing the illumination brightness. In addition, when the component is turned off, a forward bias can be applied to the gate electrode, and the hole in the HTL layer can be completely depleted, so that the OLED element is completely turned off, and the brightness is minimized. In this way, the contrast of the display device can be improved, and the pixel density (Pixels per inch; PPI) can be improved, which is advantageous for preparing a display device with a higher PPI.

The integrated component of the present invention can achieve bottom, top, and bidirectional illumination, depending on whether the gate electrode and the germanium electrode (cathode or anode) are transparent. The semiconductor material used in the integrated component is an organic material, and is particularly suitable for use in flexible display devices.

In summary, the integrated organic light-emitting diode and the thin film transistor of the present invention can integrate the switching element and the light-emitting element. The aperture ratio is increased to improve the contrast of the display device. In addition, the manufacturing process is simple, the production cost is low, and the soft substrate can be well compatible, which has high application value.

Those skilled in the art will appreciate that modifications and refinements made without departing from the scope and spirit of the invention as disclosed in the appended claims are within the scope of the invention.

1‧‧‧Substrate

2‧‧‧ gate electrode

3‧‧‧Insulation

4‧‧‧ active layer

5‧‧‧ source electrode

6‧‧‧汲 structure

61‧‧‧Lighting layer

62‧‧‧Electronic transport layer

63‧‧‧Electronic injection layer

64‧‧‧汲 electrode

7a‧‧‧Channel area

Claims (26)

An organic light-emitting element comprising: a gate electrode; an insulating layer disposed on the gate electrode; and an active layer disposed on the insulating layer, the active layer including a source region at an outer periphery thereof, a germanium region at a central portion thereof, and a source region a channel region between the germanium region; an organic light-emitting layer on the germanium region; a germanium electrode on the organic light-emitting layer; and a source electrode in the source region. The organic light emitting element according to claim 1, wherein the source electrode is disposed on the active layer. The organic light emitting element according to claim 1, wherein the source electrode is disposed on the insulating layer. The organic light-emitting element according to claim 1, wherein the source region, the channel region, and the germanium region have a square shape. The organic light-emitting element according to claim 1, wherein the gate electrode is an indium tin metal oxide, Al, Mo, Ag or graphene material. The organic light-emitting element according to claim 1, wherein the insulating layer is SiO ₂ , SiN _x , Al ₂ O ₃ or an organic polymer. The organic light-emitting element according to claim 1, wherein the insulating layer has a single layer or a multilayer structure. The organic light-emitting element according to claim 1, wherein the active layer is a P-type or N-type organic semiconductor material. The organic light-emitting element according to claim 8, wherein the active layer is an organic small molecule layer formed of an organic small molecule material or an organic small molecule doping material, or a stack including at least two layers of the organic small molecule layer Layer structure. The organic light-emitting element according to claim 8, wherein the active layer is an organic polymer layer formed of an organic polymer material or an organic polymer dopant material, or is composed of at least two layers of the organic polymer layer. Laminated structure. The organic light-emitting element according to claim 8, wherein the active layer is formed by an evaporation, coating or printing process. The organic light-emitting element according to claim 1, further comprising: a carrier transport layer and a carrier injection layer between the light-emitting layer and the germanium electrode. The organic light-emitting element according to claim 12, wherein at least one of the light-emitting layer, the transport layer, the injection layer and the germanium electrode is formed by an evaporation process, a coating process, or a printing process. The organic light emitting device according to claim 11, wherein the gate electrode is on a substrate. The organic light emitting device according to claim 14, wherein the substrate is a glass substrate or a flexible substrate. The organic light-emitting element according to claim 1, wherein the source electrode is a metal layer formed of at least one of Au, Mg, Ca, Ag, Al, Cu, or a stacked structure including two or more metal layers . The organic light-emitting element according to claim 16, wherein, in the laminated structure, at least one layer includes a metal having a work function lower than 4.3 eV, and at least another layer includes a metal having a work function higher than 4.3 eV. A method of manufacturing an organic light emitting device, comprising: forming a gate electrode on a substrate; forming an insulating layer on the gate electrode; forming an active layer on the insulating layer, the active layer including a source region at an outer periphery thereof, at a central portion thereof a squatting area, and a passage area between the source area and the squatting area; Forming a source electrode in the source region; forming an organic light-emitting layer on the germanium region; and forming a germanium electrode on the light-emitting layer. The method of claim 18, wherein the active layer is formed of an organic semiconductor material. The method of claim 18, wherein the insulating layer is an inorganic insulating layer comprising at least one of SiO ₂ , SiN _x , Al ₂ O ₃ , or an organic polymer insulating layer. The method of claim 18, wherein the insulating layer is a single layer or a plurality of layers. The method of claim 18, wherein the insulating layer is formed using a PECVD process. The method of claim 18, wherein the insulating layer is an organic polymer and is formed using a spin coating process. The method of claim 18, wherein the active layer is formed using an evaporation, coating, or printing process. The method of claim 18, further comprising: forming the light An electron transport layer and an electron injection layer between the layer and the germanium electrode. The method of claim 18, further comprising: forming a hole transport layer and a hole injection layer between the light emitting layer and the germanium electrode.