A transparent cathode structure and silicon-based organic light-emitting diode

Abstract

The utility model discloses a transparent cathode structure and a silicon-based organic light-emitting diode, which relates to the technical field of diode accessories, including sequentially arranging a first organic film layer, a rare earth metal oxide layer, a second organic film layer and a transparent metal oxide layer. The cathode structure of the utility model has high electron injection efficiency and excellent electron transmission performance, and can effectively improve the photoelectric performance of the organic light-emitting diode device without affecting the brightness and current efficiency of the white light OLED device, significantly reduce its operating voltage, and thus improve its power efficiency.

Description

Technical Field

[0001] The utility model relates to the technical field of diode accessories, in particular to a transparent cathode structure and a silicon-based organic light emitting diode. Background Art

[0002] OLED (Organic Light-Emitting Diode) is a current-type organic light-emitting device. It is a phenomenon that emits light through the injection and recombination of carriers. The luminous intensity is proportional to the injected current. Under the action of the electric field, the holes generated by the anode and the electrons generated by the cathode of the OLED will move, inject into the hole transport layer and the electron transport layer respectively, and migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, which excite the light-emitting molecules and finally produce visible light. Silicon-based Organic Light-emitting Diode (Silicon-based Organic Light-emitting Diode) is a key component unit device of the organic light-emitting diode (OLED) microdisplay. The unit device is usually composed of electrodes and multiple organic film layers. The electrodes of the unit device are divided into a reflective anode and a transparent cathode. The electron injection performance of the transparent cathode directly affects the photoelectric performance of the electronic device.

[0003] The traditional transparent cathode structure is a stacked structure composed of a metal (or metal salt) with a low work function and a transparent metal oxide (or ultra-thin metal). The driving voltage of an OLED device using the above cathode structure is relatively high, resulting in low power efficiency. Currently, there is an urgent need for a cathode structure with high electron injection efficiency and excellent electron transmission performance to improve the photoelectric performance of OLED unit devices. Utility Model Content

[0004] The purpose of the utility model is to provide a transparent cathode structure and a silicon-based organic light emitting diode to solve the problems existing in the above-mentioned prior art, so as to reduce the driving voltage of the OLED unit device and thus improve its power efficiency.

[0005] To achieve the above purpose, the utility model provides the following solutions:

[0006] The utility model provides a transparent cathode structure, which comprises a first organic film layer, a rare earth metal oxide layer, a second organic film layer and a transparent metal oxide layer which are arranged in sequence, wherein the first organic film layer is arranged on an electron transport layer.

[0007] Preferably, the first organic film layer, the rare earth metal oxide layer, the second organic film layer and the transparent metal oxide layer are all stacked by vapor deposition.

[0008] Preferably, the material of the first organic thin film layer includes ET314, Bephen, B3PyMPM, DBFTrz, TPBi, TmPyPB, Bepp2 or Alq3.

[0009] Preferably, the material of the rare earth metal oxide layer includes Yb2O3, La2O3, Ce2O3, CeO2, Sm2O3, Gd2O3, Er2O3, Y2O3 or Sc2O3.

[0010] Preferably, the material of the second organic thin film layer includes HATCN.

[0011] Preferably, the material of the transparent metal oxide layer includes IZO, AZO, ITO, SnO or ZnO.

[0012] Preferably, the thickness of the first organic thin film layer, the rare earth metal oxide layer and the second organic thin film layer is 1 nm-20 nm.

[0013] Preferably, the transparent metal oxide layer has a thickness of 100 nm-200 nm.

[0014] The utility model also discloses a silicon-based organic light-emitting diode, comprising the above-mentioned transparent cathode structure, electron transport layer, light-emitting layer, hole transport layer and anode structure arranged in sequence, wherein the anode structure is integrated on the silicon-based backplane through semiconductor technology.

[0015] Compared with the prior art, the utility model has achieved the following technical effects:

[0016] The cathode structure of the utility model has high electron injection efficiency and excellent electron transmission performance. It can effectively improve the photoelectric performance of the organic light emitting diode device without affecting the brightness and current efficiency of the white light OLED device, significantly reduce its operating voltage, and thus improve its power efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 This is a schematic diagram of the layer structure of the transparent cathode structure in the embodiment of the utility model;

[0019] In the figure: 1-first organic thin film layer, 2-rare earth metal oxide layer, 3-second organic thin film layer, 4-transparent metal oxide layer, 10-transparent cathode structure. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] The purpose of the utility model is to provide a transparent cathode structure and a silicon-based organic light emitting diode to solve the problems existing in the prior art, so as to reduce the driving voltage of the OLED unit device and thus improve its power efficiency.

[0022] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] Embodiment 1

[0024] like Figure 1 As shown, in this embodiment, a transparent cathode structure 10 is provided, which includes a first organic film layer 1, a rare earth metal oxide layer 2, a second organic film layer 3 and a transparent metal oxide layer 4 arranged in sequence. The first organic film layer 1 is directly deposited on the electron transport layer.

[0025] As an optional solution, in this embodiment, the first organic film layer 1, the rare earth metal oxide layer 2, the second organic film layer 3 and the transparent metal oxide layer 4 are all stacked by vapor deposition.

[0026] As an optional solution, the material of the first organic film layer 1 in this embodiment includes ET314, Bephen, B3PyMPM, DBFTrz, TPBi, TmPyPB, Bepp2 or Alq3. The first organic film layer 1 is an electron transport type organic semiconductor material, and its main purpose is to provide a band gap energy state in the first organic film 1 layer after the subsequent deposition of the rare earth metal oxide 2 to improve electron injection.

[0027] As an optional solution, the material of the rare earth metal oxide layer 2 in this embodiment includes Yb2O3, La2O3, Ce2O3, CeO2, Sm2O3, Gd2O3, Er2O3, Y2O3 or Sc2O3. The main purpose of the rare earth metal oxide layer 2 is to provide a band gap energy state to the first organic film layer 1 to improve electron injection.

[0028] As an optional solution, the material of the second organic thin film layer 3 in this embodiment includes HATCN. The purpose of the second organic thin film layer 3 is to prevent the rare earth metal oxide 2 from being damaged during the sputtering coating of IZO.

[0029] As an optional solution, the material of the transparent metal oxide layer 4 in this embodiment includes IZO, AZO, ITO, SnO or ZnO. The transparent metal oxide layer 4 mainly plays the role of light transmission and conduction with external circuits.

[0030] As an optional solution, in this embodiment, the thickness of the first organic thin film layer 1, the rare earth metal oxide layer 2 and the second organic thin film layer 3 is 1 nm-20 nm.

[0031] As an optional solution, in this embodiment, the thickness of the transparent metal oxide layer 4 is 100 nm-200 nm.

[0032] Embodiment 2

[0033] In this embodiment, a silicon-based organic light-emitting diode is provided, comprising the above-mentioned transparent cathode structure 10, an electron transport layer, a light-emitting layer, a hole transport layer and an anode structure arranged in sequence. The anode structure is integrated on a complementary metal oxide semiconductor (CMOS) silicon-based backplane through a semiconductor process.

[0034] Table 1 Comparison of performance indicators of the embodiment device and the reference device

[0035]

[0036] The OLED devices used for verification in Table 1 are all white light OLED devices deposited on an Al / Mo reflective anode, and a multilayer organic functional film (light-emitting layer) including a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer is sequentially deposited on the Al / Mo anode structure. The reference device and the silicon-based organic light-emitting diode in this embodiment have the same structure (including the electron transport layer, the light-emitting layer, the hole transport layer, and the anode structure) except for the difference in the transparent cathode structure 10, as shown in Table 2.

[0037] Table 2 Comparison of transparent cathode structures of the embodiment device and the reference device

[0038]

[0039] Among them, the cathode structure of the reference device 1-1 is a combination of a traditional transparent low work function metal (Yb) and a transparent metal oxide (IZO); the embodiment devices 1-2 and 1-3 both use a combined transparent cathode structure 10 of a first organic film layer 1 (ET314), a rare earth metal oxide layer 2 (Yb2O3), a second organic film layer 3 (HATCN) and a transparent metal oxide layer 4 (IZO).

[0040] The cathode structure of this embodiment has the advantage of significantly lower voltage compared to the existing structure. Theoretically, the new cathode structure adds two layers of organic film and one layer of metal oxide. The conductivity of these materials is not as good as Yb, but the voltage is reduced. This is because the special mechanism of the injection layer helps the electron injection of the device: the metal oxide undergoes a charge transfer reaction with the organic layer to generate a new energy gap state, and the electrons are directly injected into the device from the new energy gap state, thereby improving the electron injection efficiency, resulting in a decrease in the device driving voltage and improved efficiency.

[0041] Device performance comparison is based on four performance indicators of OLED devices: 2 The working voltage, brightness, current efficiency and power efficiency under the same conditions. By comparing the embodiment devices 1-2 and 1-3 with the reference device 1-1, the working voltage is reduced from 9.32V to 6.10V, and the reduction ratio is as high as 35%; the brightness is slightly improved, the current efficiency is slightly improved, and the power efficiency is improved from 8.6lm / W to 13.2m / W, and the improvement ratio is as high as 53%. It can be seen that the transparent cathode structure 10 in this embodiment can significantly reduce its working voltage to improve its power efficiency without affecting the brightness and current efficiency of the white light OLED device. Therefore, it can be obviously known from the experimental data that the cathode structure in this embodiment can significantly reduce the electron injection barrier to improve the performance of the organic optoelectronic device.

[0042] The present invention uses specific examples to illustrate the principle and implementation of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A transparent cathode structure, characterized in that: The method comprises sequentially arranging a first organic film layer, a rare earth metal oxide layer, a second organic film layer and a transparent metal oxide layer, wherein the first organic film layer is arranged on the electron transport layer.

2. The transparent cathode structure according to claim 1, characterized in that: The first organic film layer, the rare earth metal oxide layer, the second organic film layer and the transparent metal oxide layer are all stacked by vapor deposition.

3. The transparent cathode structure according to claim 1, characterized in that: The material of the first organic thin film layer includes ET314, Bephen, B3PyMPM, DBFTrz, TPBi, TmPyPB, Bepp2 or Alq3.

4. The transparent cathode structure according to claim 1, characterized in that: The material of the rare earth metal oxide layer includes Yb2O3, La2O3, Ce2O3, CeO2, Sm2O3, Gd2O3, Er2O3, Y2O3 or Sc2O3.

5. The transparent cathode structure according to claim 1, characterized in that: The material of the second organic thin film layer includes HATCN.

6. The transparent cathode structure according to claim 1, characterized in that: The material of the transparent metal oxide layer includes IZO, AZO, ITO, SnO or ZnO.

7. The transparent cathode structure according to claim 1, characterized in that: The thickness of the first organic thin film layer, the rare earth metal oxide layer and the second organic thin film layer is 1 nm-20 nm.

8. The transparent cathode structure according to claim 1, characterized in that: The thickness of the transparent metal oxide layer is 100nm-200nm.

9. A silicon-based organic light-emitting diode, characterized in that: It comprises the transparent cathode structure according to any one of claims 1 to 8, an electron transport layer, a light-emitting layer, a hole transport layer and an anode structure arranged in sequence, wherein the anode structure is integrated on a silicon-based backplane through a semiconductor process.

Images