Tuning of opto-electronic properties of Cu2SnS3 thin films through variation of stoichiometry

Copper Tin Sulfide (Cu2SnS3), one of the promising absorber layer for thin film solar cell, was successfully deposited on glass substrate maintained at a substrate temperature of 325° C by chemical spray pyrolysis technique (CSP). Variation in copper concentration in the precursor solution affects the structural, optical and electrical properties of the films. XRD results proved the tetragonal structure (with preferential orientation along (112) orientation) of the samples. All samples were p-type and their band gap and resistivity decreased with increase in Copper concentration. A minimum resistivity of 1.6×10−3 Ω.cm was obtained for an optimum copper concentration