INFLUENCES OF FLUX OF CARRIER GAS ON MICROSTRUCTURE AND MORPHOLOGIES OF CIGS FILMS

摘要

CuInGa (CIG) precursors were deposited on the substrate of Mo-coated soda-lime glass with middle frequency a. c. magnetron sputtering. Then the Cu(In1-xGax)Se2 (CIGS) absorbers were obtained by selenizing the CIG precursors in the atmosphere of Se vapor. Ar or N2 was used as carrier gas to carry Se vapor into selenization furnace from heated Se source. The influences of carrier gases on microstructure and morphologies of CIGS thin films are investigated. The CIGS films were characterized with X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy to evaluate the microstructure, morphology, and composition, respectively. The results show that the microstructures of the CIGS films are mainly of chalcopyrite phase with a (112) preferred orientation. When the carrier gas is N2, the CIGS film is compact at the flux of 0.40m3/h, and turns loose with the reduction of the N2 flux. When the carrier gas is Ar, the CIGS film is compact at the flux of 0.10m3/h, and turns loose with the increase of the Ar flux. The CIGS film with ideal elemental composition of weak p-type is obtained at the N2 flux of 0.40m3/h.