Photo-electrochemical behavior of CIGS solar thin films prepared through a novel CISe/Ga-Se two–step electrochemical stack approach

Abstract

Copper indium selenide (CuInSe2 or CIS) thin films were electrodeposited on FTO substrates by co-electrodeposition of Cu-In-Se precursor thin films using an electrolyte comprised of Citric acid-SDS. By the addition of SDS, the formation of CIS nanoislands were avoided which can create compositional non-uniformity. They were further annealed at 400 ˚C in nitrogen atmosphere. The structural, compositional, optical and electronic characterization of asdeposited and annealed CIS thin films were investigated by XRD, Raman, FE-SEM/EDAX, UV-VIS spectroscopy and electrochemical analysis. With an optical bandgap of approximately 1 eV, the annealed CIS thin film exhibited a p-type behavior with excellent photoelectrochemical properties.