High-efficiency, Cd-free copper–indium–gallium–diselenide/polymer hybrid solar cells

The use of a semiconducting polymer as a buffer layer replacement for CdS in traditionally all-inorganic copper–indium–gallium–diselenide (CIGS)-based solar cells is reported. The semiconducting polymer used is poly(benzimidazobenzophenanthroline) (BBL), which has physical and electronic properties that facilitate a suitable junction between the CIGS and the top electrode. We report on the fabrication, physical properties and photovoltaic characteristics of such Cd-free organic–inorganic devices, which have 6% power-conversion efficiencies.