The Influence Of Heat-reatment Conditions On Properties CuInS₂Thin Films

The high pure Cu,In,S powder mixed by the ratio of1:0.1:1.2was put on the molybdennum boat to prepare CuInS2thin films by single source co-evaporation technology,condated in N2environment.The influence of heat-treatment process on the properties of the thin films were studied indetailed.The optimum heat-treatment condition was abtain to contruct the conductivity type conversion of the CuInS2thin films.The structure,thickness,surface morphology roughness,inner chemical composition as well as electronic and optical properties of the films were characterized by the X-ray diffraction, manual profiler,scanning electron microscopy with energy dispersive analysis,ultraviolet-visible spectrophotometer, Holzer effect tester et al.It was found experimentally that reasonable heat-treatment is the key to investigate the conversion of conductive type of CuInS2thin films, In this thesis,the CuInS2thin film was prepared by use of heat-treatment at360℃for30mins. It was found the film formed to N-type chalcopyrite structure,which was grown along with the characteristical peak of the (112) direction.The average grain size (29.43nm),the surface roughness (1392nm),the absorption coefficiency (1×104m-1) were obtain experimentally.The optical bandgap of the film was measured as1.38eV, which closed to the ideal band width1.45eV for the high-efficient solar cell.The resistance of the thin film is1.576×10-3Ω·cm. Stoichiometrie of body’s elements in thin film was1:1.2:1.6,which deviate6.6%～7.9%to standard stoichiometry.The crystalline structure of thin film kept unchangeed when heat-treatment temperature raise to370℃,The conductor type and the absorption coefficiency were P-type and2.2×104cm-1,the optical bandgap and the resistance were1.37eV and2.095×10-3Ω·cm.It can be concluded that the proper heat-treatment process can not only improve crystallization and electronic and optical properties of the CuInS2thin film but also control the component content of the film better. For more content of In,the film conductior type is N-type,Conversely, the film conductcor type is P-type.