Electrochemical etching of the CuIn0.7Ga0.3Se2 absorber films prepared by non-vacuum process

Hsing I. Hsiang, Hung Yi Lin, Brahma Sanjaya, Yu-Min Shen

研究成果: Article同行評審

摘要

In this study, the chalcopyrite (CuIn0.7Ga0.3Se2, CIGS) powders were synthesized by the heating-up method and CIGS light-absorbing layer films were prepared by non-vacuum slurry coating method followed by sintering under different atmospheres. The surface roughness of the as-prepared film was usually higher and the secondary phase in the form of Cu2-xSe often appeared on the surface of the film, which led to the decrease in the conversion efficiency. A simple electrochemical etching process was used to modify the surface of CIGS light-absorbing layer and improve the photoelectric conversion efficiency. The current density of CIGS thin films was promoted from 1.78 mA/cm2 to 3.58 mA/cm2 by using electrochemical etching process. The highest current density of 3.94 mA/cm2 was obtained by optimizing the number of cyclic voltammetry cycles and thickness of the CdS buffer layer. The surface roughness of the CIGS film was reduced after electrochemical etching process leading to the decrease in the resistance between grain boundaries, increase in the carrier mobility, and hence increase the photoelectric conversion efficiency. Moreover, the chemical composition changed from copper rich to copper deficiency. The N-type Cu(In1-xGax)3Se5 (order vacancy compound, OVC) was formed on the CIGS surface, and hence a pseudo-homo-junction was built. This pseudo-homo-junction facilitates the conversion efficiency of the p-n junction of the CdS buffer layer-CIGS and the light-induced charge separation. The surface concentration composition of the CIGS film after electrochemical etching resulted in the energy gap match between the CdS and CIGS junctions, thereby improving the solar cell conversion efficiency.

原文English
文章編號177995
期刊Journal of Alloys and Compounds
1010
DOIs
出版狀態Published - 2025 1月 5

All Science Journal Classification (ASJC) codes

  • 材料力學
  • 機械工業
  • 金屬和合金
  • 材料化學

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