Structure of chemically deposited Zn(S,O,OH) buffer layer and the effects on the performance of Cu(in,Ga)Se2 solar cell

The effects of the immersion into a NH3 aqueous solution on the structural characteristics of the chemically deposited Zn(S,O,OH) layer and photovoltaic performance of the CIGS/Zn(S,O,OH) solar cells were investigated with structural and electrical characterizations. The as-deposited-Zn(S,O,OH) layer possessed a layered structure of upper Zn(OH)(2) and Zn(S,O) layers, and the upper Zn(OH)(2) layer was removed by the immersion. The conversion efficiency for the CIGS solar cell was improved from 6.8% to 13.7% by removing the upper Zn(OH)(2) layer during the immersion. Copyright (c) 2015 John Wiley & Sons, Ltd.