Organic photolectronic device with an updoped gain layer and preparation method thereof

Abstract

The invention discloses an organic photolectronic device with an updoped gain layer, and the structure of the device at least comprises a substrate, a first electrode layer, an organic functional layer, and a second electrode layer; wherein, the organic functional layer comprises an electron transfer layer or an electron acceptor layer, which is characterized in that updoped gain layer with the function of improving electron mobility is equipped in the electron transfer layer or the electron acceptor layer, the thickness of the gain layer is smaller than 5nm and the materials are metal or organic compound with strong electron withdraw groups. The device overcomes the defects of existing technology, improves electron mobility effectively, balances the amount of current carriers such as electrons and cavities inside the device, and has simple structure, low cost and high efficiency.

Description

technical field [0001] The invention relates to the technical field of organic optoelectronics in electronic components, in particular to an organic optoelectronic device with a non-doped gain layer. Background technique [0002] Optoelectronic devices refer to devices capable of photoelectric or electro-optical energy conversion, including photodetectors, solar photovoltaic cells, light-emitting devices and lasers. Such devices generally comprise a pair of electrodes called a cathode and an anode and at least one loading layer sandwiched between the cathode and anode. Depending on the function of the optoelectronic device, one or more loading layers may consist of a material or materials that emit light in response to a voltage applied to the electrodes, or the layer or layers may form a heterojunction that, when exposed to light Photoelectric effect can be produced when irradiated. Many properties of all these functional devices based on organic semiconductor materials a...

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Problems solved by technology

[0003] In the field of organic electroluminescence (OLED), in order to balance the electrons and holes in the light-emitting layer, it is reported that the light-emitting layer is doped with a compound as an electron-accepting dopant or an electron-donating dopant, see 200680016012.7 ( 2006), this patent mainly doped electron-accepting and electron-donating dopants in the light-emitting layer, and the possible result is that the dopant quenches the excitons generated in the light-emitting layer, especially the doping of alkali metal materials in the light-emitting layer In addition, the process of doping metal materials in organic materials is relatively complicated, which increases the complexity and precision of equipment, and increases the difficulty of device realization and production costs.

[0004] In order to improve the cathode electron injection and balance the electron holes, in order to reduce the potential barrier encountered when injecting electrons from the cathode to the organic compound, some studies have also introduced a metal doped layer at the interface of the cathode layer to improve the electron injection. See 98104283.X (1998), although this patent puts metal doping in the electron transport layer, because the electron transport layer is close to the light-emitting layer, the excitons in the light-emitting layer will also be quenched due to collisions with metal atoms when they diffuse , is not conducive to improving device performance

At the same time, the doping of metal materials in electron transport materials is also a mixture of organic materials and inorganic materials, which is difficult to realize and is not conducive to reducing the cost of device manufacturing.

[0005] In addition, the method of setting a buffer layer doped with alkali metal fluoride or alkaline earth metal fluoride between the electron transport layer and the cathode, see 200510069612.7 (2005) for details, for metal materials and organic materials and mixed preparation will increase the process difficulty of device preparation, At the same time, it may affect the film-forming characteristics of the material, thereby affecting the performance of the device

[0006] In addition, metal or metal salt doping is used to form an electron injection layer at the interface of the electron transport layer to improve electron injection. See 01807496.0 (2003) for details. The effect of this patent is limited to the effective injection of electrons. For electrons in the electron transport layer The contribution to the improvement of mobility is not obvious enough. If electrons cannot recombine with holes to form excitons within the effective lifetime, the accumulation of excess electrons in the electron transport layer will also affect the performance of the device.

[0007] In recent years, although organic optoelectronic technology has made great progress, the current technology still has many bottlenecks in the field of organic optoelectronic devices: making simple structural devices, cost, and efficiency are all important factors affecting the practical use of devices, and Because the electron transfer rate is much lower than the hole transfer rate inside the device, the imbalance between electrons and holes in the transport process seriously affects the formation of excitons, resulting in low device efficiency.

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