A preparation method of micron-sized copper-germanium-zinc-tin-sulfur single crystal particles, single crystal particles and solar cells

Abstract

The invention discloses a preparation method of a micro-grade copper, germanium, zinc, tin sulfur single crystal particle, the single crystal particle and a solar battery. The method comprises the following steps: firstly mixing reaction materials according to a designed formula to prepare precursor, performing vacuum packaging on the precursor, and fusing the precursor at certain temperature to produce CGZTS single crystal particle; in addition, taking epoxy resin and Arabic gum as macromolecular materials, embedding the micro-grade CGZTS single crystal particle into the macromolecular materials to prepare a single crystal particle film, and then preparing various functional layers to form a complete battery. As the preparation of the single crystal particle and the preparation process of a single crystal particle absorption layer film are separated from each other, and high temperature environment can be adopted during the preparation of the single crystal particle, the CGZTS component can be effectively controlled, the influence on a substrate, a window layer and a buffer layer by the preparation condition of an absorption layer is not required to be taken into account, and the method has obvious advantages in terms of material and energy utilization rate and industrial production.

Description

technical field [0001] The invention relates to the technical field of semiconductor optoelectronic materials and devices, more specifically, to a method for preparing micron-sized copper-germanium-zinc-tin-sulfur single crystal particles, single crystal particles and solar cells. Background technique [0002] Multi-component CuInGaSe 2 (CIGS) thin-film solar cell has high conversion efficiency and is easy to mass-produce, and has become the most promising solar cell material at present. Currently, CIGS cell is the thin-film solar cell with the highest photoelectric conversion efficiency in the world, and its highest conversion efficiency has been up to 21.7%. However, its constituent elements In and Ga are scarce on the earth, making it difficult for CIGS thin-film batteries to achieve TW (10 9 kW) level of large-scale applications. [0003] Copper-zinc-tin-sulfur (CZTS)-based thin films are considered to be the most promising new compound semiconductors to replace the a...

AI Technical Summary

Problems solved by technology

The diffusion length of carriers in the CZTS-based film is too small, resulting in the inability to effectively collect the charges generated deep in the material, and it is difficult to improve the conversion efficiency of the device. If the energy band width of the CZTS film can be effectively regulated, it will guide and enhance the electron density. Diffusion from the depth of the film to the surface, thereby greatly improving the charge collection efficiency to increase the current of the device, and at the same time increasing the open circuit voltage of the device is also very critical for improving the efficiency of the device

[0004] At present, the preparation of the absorption layer of CZTS-based solar cells mainly focuses on vacuum processes such as multivariate co-evaporation, pulsed laser deposition, sulfidation and selenization after sputtering, selenization and sulfidation after electrochemical film formation, and heat injection, solvothermal, hydrothermal methods, spraying, etc. In non-vacuum processes such as pyrolysis, compared with binary and ternary compound semiconductors, CZTS-based compound semiconductors have more complex physical properties due to the increase in constituent elements, so the high-efficiency thin-film batteries of this type of compound Preparation and performance optimization become more difficult; at the same time, the thermodynamically stable region of the CZTS phase is very small, and various impurity phases and metastable phases compete with CZTS. Therefore, in the preparation process of CZTS-based thin films, if effective component control is not achieved, Due to the volatilization of some elements, the deviation from the stoichiometric ratio is easily accompanied by various binary and ternary impurity phases and some metastable phases, which will eventually have an adverse effect on the performance of CZTS-based batteries; when preparing solar cells, single crystal cells The performance of solar cells is better than that of thin-film batteries, but traditional single crystal growth techniques (vapor phase transport technology, melting technology) are difficult to grow large-sized single crystals that meet the performance requirements of the solar cell absorber layer.

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