Optical and electrochemical properties of CuInSe2and CuInS2hyphen;CuInSe2alloys

摘要

The fundamental optical transitions in single crystals of CuInS2xSe2minus;2xalloys have been studied by electrolyte electroreflectance (EER) spectroscopy. The band gap of the alloys increases nonlinearly with increasing sulphur content corresponding to a bowing parameter 0.14. The flatband potential derived from the EER spectra is in excellent agreement with differential capacitance measurements and determined as minus;0.350 V versus the saturated calomel electrode. CuInS2xSe2minus;2xliquid junction solar cells are reported that exhibit a long wavelength cutoff in the spectral response matching the EER data.