In this work CZTS thin films were prepared on n-type si substrate with successive (1-7) layers by chemical spray pyrolysis. Copper chloride (CuCl2,2H2O), zinc acetate dehydrate (C4H10O6Zn, 2H2O), tin chloride (SnCl4,5H2O) and thiourea [(NH2)CS] were used as precursor materials. A home-made chemical spray pyrolysis system is used to prepare CZTS thin films. The solution was sprayed using nitrogen as a carrier gas. The substrate temperature was kept at 350°C and spray pyrolysis nozzle rate was 2 ml per minute. The thickness and the surface homogeneity of films were measured through SEM and FE-SEM. The XRD results from the films showed an increase in the intensity of the peaks obtained from the (112), (220) and (312) planes (which are the characteristic peaks of the kesterite structure) with the increase in the number of layers. Also the energy band gap determined from UV-Vis spectrum is 1.7 eV. The Raman spectrum of all samples show a single Raman intense peak located at 332 cm-1. XRD and Raman spectrum results prove that only a single phase CZTS is formed during chemical spray pyrolysis technique. There are two more peaks at around 650cm-1 and 900cm-1 which are related to ZnS phase. These peaks which are less intense compared to CZTS peak may be due to low concentration of Zn and also to the low annealing temperature (350 °C).
Anahtar Kelimeler: Thin Film, CZTS, XRD, Photo-Voltaic, Annealing