Elaboration et caractérisation de couches absorbantes des cellules solaires en couches minces à base de Cu2ZnSnS4

Abstract

Among the most promoter quaternary semiconductors for the thin film solar cells fabrication, the Cu2ZnSnS4. Our choice is oriented on the quaternary thin film Cu2ZnSnS4 (CZTS) as a new film absorber with good physical properties (band gap energy from 1.4 to 1.6 eV with a large absorption coefficient over 104 cm-1). In addition, whose impact on the environment is very harmful. This part is carried in order to optimize the different parameters and to understand the growth mechanism of films deposited by spray method. These layers are analyzed by various techniques of characterization of materials. We have repaired a set of CZTS thin film with variable conditions such as substrate temperature, deposition time and salt of Zn source. The various deposited characterizations have shown that the fundamental properties depend on the deposition conditions. The XRD spectra have shown that films obtained from Zinc acetate have a coexistence of crystalline phase orientation CZTS preferentially along the direction [112] and a phase secondary ZnSnO3. The value of the optic gap varies from 1.4 to 1.6 eV, one places the thin films of CZTS like a serious candidate for their use like absorbing layer in the cells solar in thin film. The electrical measurements indicated that the films conductivity varies in [0.7 – 6 (Ω.cm)-1].