The post-growth effect on the properties of Cu2ZnSnS4 thin films

Abstract

Cu2ZnSnS4 (CZTS) thin film was deposited on glass substrate by spray pyrolysis technique using a methanolic solution. This film was annealed under nitrogen atmosphere for an hour at different annealing temperatures. The effect of the annealing temperature on composition, structure, morphology, electrical, and optical properties of CZTS films was investigated. Energy dispersive x-ray analysis showed that after the annealing process, the atomic ratio values tend to their stoichiometric values. Moreover, the X-ray diffraction (XRD) and Raman spectroscopy revealed a kesterite structure with (112) preferential orientation for both as-deposited and annealed CZTS films. Moreover, they exhibited an improvement in crystallinity after annealing which was confirmed by SEM analysis. The conductivity of the heated CZTS films showed also an important increase in crystallinity. The absorption edge shifted toward lower wavelengths leading to an increase in band gap energy for the annealed CZTS films.