Structural and optical properties of Cu2ZnSnS4 thin film absorbers from ZnS and Cu3SnS4 nanoparticle precursors

Cu2ZnSnS4 (CZTS) has been considered as an alternative absorber layer to Cu(In, Ga)Se-2 due to its earth abundant and environmentally friendly constituents, optimal direct band gap of 1.4-1.6 eV and high absorption coefficient in the visible range. In this work, we propose a solution-based chemical route for the preparation of CZTS thin film absorbers by spin coating of the precursor inks composed of Cu3SnS4 and ZnS NPs and annealing in Ar/H2S atmosphere. X-ray diffraction and Raman spectroscopy were used to characterize the structural properties. The chemical composition was determined by energy dispersive X-ray spectroscopy. Optical properties of the CZTS thin film absorbers were studied by transmission, reflection and photoluminescence spectroscopy. (C) 2012 Elsevier B.V. All rights reserved.