Single-Step Electrodeposition of CZTS Thin Film for Solar Cell Application: Effect of Annealing Time

Abstract

Silicon-based solar cells are widely used solar cells, but it needs a very thick absorber layer. Absorber layers based on cadmium telluride (CdTe), copper indium gallium diselenide (CIGS), copper indium diselenide (CIS), and copper zinc tin sulfide (CZTS) are extensively studied for thin-film solar cells. The use of CdTe for thin-film solar cells is less preferred due to its toxicity. In comparison with CIGS, thin-film solar cells with CZTS absorber layers are preferred since the raw materials are earth-abundant, nontoxic, and inexpensive. The CZTS materials have a high absorption coefficient of 104 cm−1 and have the band gap energy of 1.4–1.5 eV. In this work, single-step electrodeposition of Cu2ZnSnS4 (CZTS) thin-film on gold-coated slide using glycine as a complexing agent was carried out. The effect of different annealing time on surface morphology, crystallite size, and its elemental composition was studied. X-ray diffraction (XRD) analysis reveals the kesterite phase of CZTS. Crystallite size increases with increase in the annealing time. Deposited CZTS thin film annealed for 30 min shows the elemental composition near to the desired stoichiometry (Cu:Zn:Sn:S = 2:1:1:4).