Structure and Electrical Property of CuInS_2 Thin Films Deposited by DC Reactive Magnetron Sputtering

CuInS2 thin films for solar cells were prepared on the glass substrate by DC reactive magnetron sputtering technique.Produced films were characterized by EDS,SEM,XRD,hot point probe and Hall electrical measurement.The results suggest that the composition of the films are determined and controlled by the power ratio of copper target and indium target,while the morphology of thin films depends on the composition of thin films and target power ratio.As the atomic ratio [Cu]/[In] increases,the film phases transform from the In-rich phases to CuInS2 phases.Although increasing atomic ratio [Cu]/[In] can improve the crystalline quality of CuInS2 thin films,high [Cu]/[In] in Cu-rich thin films will lead to the declination of crystalline quality.Cu-rich or slightly Cu-poor CuInS2 films show P-type conducting.With the increase of the atomic ratio [Cu]/[In],the carrier concentration and the carrier mobility of CuInS2 thin film raises,but the resistivity declines sharply.It is also found that and the carrier concentration and carrier mobility of the Cu-rich CuInS2 films are much higher than that of Cu-poor ones.