Growth and characterization of chalcostibite CuSbSe <inf>2</inf> thin films for photovoltaic application

Bulk copper antimony selenide was synthesized using mechanical alloying from the elemental precursors. Phase formation in milled powders was studied using x-ray diffraction (XRD) and Raman spectroscopy studies. The synthesized bulk source after cold compaction was used as source material for thin film deposition by e-beam evaporation. Thin film deposition was carried out at various e-beam current values (I b ∼30, 40 and 50 mA) and at a substrate temperature of 200 °C. Near stoichiometric CuSbSe 2 thin films were obtained for I b values closer to 50 mA and post annealing at a temperature of 380 °C for 1 h. Thin films deposited using above conditions were found to exhibit an absorption coefficient (α) values of >10 5  cm −1 and a band gap value ∼1.18 eV that is closer to the reported band gap for CuSbSe 2 compound.