CdTe nanometer crystalline heterojunction solar battery and manufacturing method thereof

Abstract

The invention belongs to the field of photoelectric devices, and discloses a CdTe nanometer crystalline heterojunction solar battery and a manufacturing method of the CdTe nanometer crystalline heterojunction solar battery. The CdTe nanometer crystalline heterojunction solar battery is formed by a glass substrate, a negative electrode, a negative electrode interface layer, a window layer, an optical activity layer and a positive electrode in a sequentially stacked mode. The negative electrode interface layer is a ZnO film or a TiO2 film. The optical activity layer is composed of one or more CdTe nanometer crystalline layers. The negative electrode is at least one of an indium tin oxide conductive film, doped stannic oxide, a metal film and a metal oxide film. The window layer is a CdS film. The positive electrode is made of Ag or Al. A MoO3 oxidation film is arranged between the optical activity layer and the positive electrode. According to the CdTe nanometer crystalline heterojunction solar battery, the solution machining technology is used, the ultra-thin solar battery is achieved, the performance is excellent, and the energy conversion efficiency is as high as 3.73%.

Description

technical field [0001] The invention belongs to the field of photoelectric devices, in particular to a CdTe nanocrystalline heterojunction solar cell and a preparation method thereof. Background technique [0002] Environmental degradation and energy shortage have become the main problems facing mankind in the 21st century, and the search for clean energy and renewable energy has become a common concern of all countries in the world. Solar energy is an inexhaustible and inexhaustible renewable energy source for human beings. It will not change the thermal energy balance of the earth, and it is also a clean energy source that does not produce any environmental pollution. At present, solar cells with relatively mature technology in the market are mainly inorganic solar cells based on crystalline silicon, cadmium telluride, gallium arsenide, indium phosphide, and polycrystalline compound semiconductors. Among them, crystalline silicon solar cells have been applied on a certain ...

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Problems solved by technology

Qin Donghuan and others have prepared ITO / CdTe(500nm) / Al Schottky junction solar cells by layer-by-layer spin-coating and sintering, and the energy conversion efficiency reaches 5.15%, which is the highest level of similar devices (S.Sun, H.M.Liu, Y.P.Gao , D.H.Qin, J.Materials.Chemistry., 2012, 517, 6853–6856.); Jasieniak et al. Introducing ZnO nanocrystals as the acceptor material, prepared CdTe-ZnO nanocrystal heterojunction cells with an efficiency of 7.3% and a certain degree of stability; it is worth noting that these CdTe nanocrystal solar cells, whether Schottky There are certain problems in both the structure and the heterojunction structure: the active layer CdTe is directly spin-coated on the ITO, and the light is incident from one side of the ITO, so the Schottky junction or p-n junction is on the other side away from the incident light. It is extremely unfavorable for the separation and transmission of carriers. Photogenerated carriers need to pass through a relatively thick active layer to reach the junction region, and recombination is inevitable during the transmission process, which is not conducive to making full use of the incident sunlight; on the other hand , ITO is used as the anode, and the cathode mainly uses low work function metals such as Al, which is easy to oxidize, and the stability of the device is difficult to be guaranteed.

Another relatively successful nanocrystalline solar cell is PbS-PbSe nanocrystals. In 2010, Sargent et al. (J.Tang, X.Wang, L.Brzozowski, D.A.R.Barkhouse, R.Debnath, L.Levina, E.H.Sargent, Adv.Mater.,2010,22,1398.) reported PbS nanocrystalline Schottky solar cells, the structure of the device is ITO / PbS / LiF / Al, and the short-circuit current and open-circuit voltage of the device are 14mA / cm 2 and 0.51V, the fill factor reaches 51%, and the corresponding efficiency reaches 3.6%; recent studies have increased the efficiency of this structure device to 4.07% by introducing organic interface materials; at the same time, the Sargent research group (J.Tang, H . Liu, D. Zhitomirsky, S. Hoogland, X. Wang, M. Furukawa, L. Levina, E. H. Sargent, Nano Lett, 12 (2012) 4889-4894.) By introducing TiO 2 The acceptor material forms a heterojunction battery with PbS, and the efficiency exceeds 7%. Most of the related work is published in Nature and its sub-journals. It is worth noting that the band gap of PbS nanocrystals can be well adjusted by adjusting the reaction conditions. Control, its corresponding absorption edge just falls in the near-infrared region, which provides very convenient conditions for the utilization of infrared spectrum, so the research has been highly valued; but these nanocrystalline batteries also have serious efficiency decline problems, how to solve this problem The problem will be the focus of future research

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