Single Step Electrodeposited Kesterite Cu2ZnSnS4 (CZTS) Thin Films at Low Annealing Temperatures

Abstract

[EN] This paper reports onthe growth of quaternary Cu2ZnSnS4 (CZTS) thin films by a single step electrochemicaldeposition followed by annealing at low temperature.The influence of different annealing atmospheres at constant annealingtimes (t = 45min) and fixed preparation controlling parameters; i.e., starting materials (precursor metal salts) solution concentration, time of deposition and electrodeposition potential. Structural, compositional, morphological, andoptical properties, as well as photoelectrochemical properties were studied. The films, sulfurized during 2 hours, showeda prominent kesterite phase with a nearly stoichiometric composition. Samples were characterizedby X-ray diffraction (XRD), scanning electron microscopy (SEM), EDS and UV-VIS-NIR spectrometry. X-ray diffraction and confirmed the formation of pure kesterite CZTS films. SEM shows that films are compact with densemorphology and homogeneous distribution. EDS analyzed the elemental constituents of the quaternary Cu2ZnSnS4 with an apparent Cu deficiency and S rich for the sulfurized samples. From optical study, the energy gap was indexed for the sulfurized samples,Eg=1.52 eV. Under illumination sulfurized CZTS films exhibits negative photocurrent and positive photovoltagevalues confirming the p-type character of the films.