Enhancing the open-circuit voltage in narrow-bandgap CuInSe2 solar cells via local contact passivation with Al2O3

A fabrication technique using Al2O3-passivated local contacts was employed to produce narrow-bandgap CuInSe2 (CISe) photoabsorbers, which are well-suited as bottom cell materials in tandem devices. In this study, for the first time, we attempted to improve the photovoltaic conversion efficiency (PCE) of CISe solar cells by adding a Al2O3 passivation layer.