Growth and solar cell applications of AgGaTe2 layers by closed space sublimation using the mixed source of Ag2Te and Ga2Te3

摘要

The AgGaTe2 layer growth was performed using the mixed source of Ag2Te and Ga2Te3 by the closed space sublimation method. It was expected from the phase diagram of Ag2Te-Ga2Te3 system that the AgGaTe2 could be achieved with approximately 1:1 mixing ratio, and the chalcopyrite phase would be formed at temperature around or lower than 730°C. Si substrates were used and the Ag2Te buffer layer was introduced between AgGaTe2 and Si to eliminate the melt-back etching. It was indicated that Ag2Te buffer layer was changed to the AgGaTe2 layer during the AgGaTe2 growth, and uniform AgGaTe2 layer with the abrupt interface was formed. The solar cell was fabricated using the p-AgGaTe2-Si heterojunction, and exhibited 1.15% of the conversion efficiency.