Spectral Response and Photoelectrochemical Properties of Cd_1-xZn_xSe Films

Cd_1-xZn_xSe films with different zinc contents are deposited by an electron beam evaporation technique onto glass substrates for applications in solid-state photovoltaic devices. The structural, optical and photoelectrochemical (PEC) properties of Cd_1-xZn_xSe films are studied. The host material Cd_1-xZn_xSe is prepared by the physical vapor deposition method of electron beam evaporation technique (PVD: EBE) under a pressure of 1× 10^-5 mbar. The x-ray diffractogram indicates that these alloy films are polycrystalline in nature, hexagonal structure with strong preferential orientation of the crystallites along (002) direction. The optical properties shows that the band gap E_g varies from 2.08 to 2.84 eV as zinc content varies from 0.2 to 0.8. A PEC cell of the configuration n-Cd_1-xZn_xSe/Na₂S-S-NaOH is fabricated and the dynamic current-voltage characteristics in the dark atmosphere have been examined at room temperature. It has been found that both V_oc and I_sc decrease with the photoelectrode composition x. Efficiency η and fill factor (FF) also show similar variations. The material properties would be altered and excellently controlled by controlling the system composition x.