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

Abstract

The authors have fabricated 19.52% thin-film $\mathrm{Cu}{\mathrm{In}}_{1-x}{\mathrm{Ga}}_x{\mathrm{Se}}_2$ (CIGS)-based photovoltaic devices using single layer chemical bath deposited ${\mathrm{Cd}}_{1-x}{\mathrm{Zn}}_x\mathrm{S}$ (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.