High efficiency thin-film CuIn1-xGaxSe2 photovoltaic cells using a Cd1-xZnxS buffer layer

The authors have fabricated 19.52% thin-film CuIn1-xGaxSe2 (CIGS)-based photovoltaic devices using single layer chemical bath deposited Cd1-xZnxS (CdZnS) buffer layer. The efficiency equals the world record for any thin-film solar cell and is achieved with reduced optical absorption in the window layer. Using current-voltage, quantum efficiency, and capacitance-voltage measurements, the CIGS/CdZnS device parameters are directly compared with those of CIGS/CdS devices fabricated with equivalent absorbers. (c) 2006 American Institute of Physics.