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Oxidation of CdTe thin film in air coated with and without a CdCl 2 layer
Author(s) -
Bai Zhizhong,
Wang Deliang
Publication year - 2012
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201228107
Subject(s) - cadmium telluride photovoltaics , annealing (glass) , materials science , thin film , layer (electronics) , eutectic system , chemical engineering , melting point , oxygen , oxide , solar cell , coating , analytical chemistry (journal) , chemistry , nanotechnology , metallurgy , optoelectronics , composite material , microstructure , chromatography , organic chemistry , engineering
During the fabrication process of a CdS/CdTe solar cell, oxygen is often present or intentionally introduced in the CdTe growth and annealing atmospheres. In this study a comparative study was carried out on the oxidation of thin CdTe films during the annealing process in air when coated with and without a CdCl 2 layer, respectively. It was found that the presence of a thin CdCl 2 coating layer on the CdTe film surface enhanced the oxidation of the CdTe surface. Near the film surface, the film was composed of a low‐melting eutectic mixture of CdTe and oxides of CdTe and Te. The formation of the low‐melting mixture was assisted by the much lowered melting point of CdCl 2 , the presence of oxides, and the CdTe compound. This low‐melting layer enhanced the oxygen reaction with the CdTe film. The dominant oxide was CdTeO 3 . A CdTe solar cell with an efficiency of 9.9% was fabricated with a CdTe film subjected to an annealing in air at 400 °C with the presence of a CdCl 2 coating layer.