Electrical properties of Cu2ZnSnS4 thin films deposited by spray-sandwich technique

Abstract

Cu2ZnSnS4 (CZTS) thin films were prepared by “Spray Sandwich” technique. The structural, surface morphological and electrical properties of the films were carried out by means of X-ray diffraction, scanning electron microscopy and impedance spectroscopy measurement techniques. The X-ray diffraction (XRD) pattern showed the characteristic peaks at (1 1 2), (2 2 0) and (3 1 2) planes, which correspond to Cu2ZnSnS4, thin films. The Nyquist impedance spectra exhibited depressed semicircles with equivalent circuit function as typical parallel RC. The activation energy value calculated from angular frequency relaxation and DC conductivity proved that the conduction mechanism was thermally activated by hopping between localized states. Moreover, the analysis of frequency and temperature dependence of conductivity support the correlated barrier hopping (CBH) model.