Study of kesterite Cu2ZnSnS4 (CZTS) thin films deposited by spray technique for photovoltaic applications

For the synthesis of an absorber crystalline layer of the solar cell device, the Cu2ZnSnS4 (CZTS) absorber is fabricated by using the sol–gel method and the spray deposition technique. The proposed method in this study aims to synthesize stoichiometric CZTS thin films without the sulfurization process and use of a toxic atmosphere. Thin films CZTS were sprayed on the substrates annealed at different temperatures, that are 250, 300 and 350 °C, for solar cell applications. This study highlights the effect of the substrate temperature on the structural, morphological and optical properties of the CZTS deposited films. Therefore, in this study, at the higher substrate temperature, which is 350°C, a semi-optimal band-gap value of Eg = 1.3 eV was obtained. For the all prepared CZTS thin films, the structural and optical properties were discussed in the light of the variations in the observed microstructure at different substrate temperatures.