Preparation and characterization of spray-deposited Cu2ZnSnS4 thin films

Thin films of Cu2ZnSnS4 (CZTS), a potential candidate for absorber layer in thin film heterojunction solar cell, have been successfully deposited by spray pyrolysis technique on soda-lime glass substrates. The effect of substrate temperature on the growth of CZTS films is investigated. X-ray diffraction studies reveal that polycrystalline CZTS films with better crystallinity could be obtained for substrate temperatures in the range 643–683 K. The lattice parameters are found to be a=0.542 and c=1.085 nm. The optical band gap of films deposited at various substrate temperatures is found to lie between 1.40 and 1.45 eV. The average optical absorption coefficient is found to be >104 cm−1.