Photophysical investigation of charge recombination in CdS/ZnO layers of CuIn(S,Se)2 solar cell

Excitation wavelength dependent femtosecond transient photocurrents were measured on CuIn(S,Se)2 solar cell devices, in the range of 330–1300 nm. Below 450 nm wavelength excitations, charge recombination in CdS/ZnO layers is determined to be responsible for longer decays and lower EQE. Femtosecond pump–probe measurements also support the charge transfer and recombination in CdS/ZnO layers. These measurements will be helpful to design high efficiency CISSe solar cells, by selecting suitable buffer layers.