AVS 45th International Symposium
    Thin Films Division Monday Sessions
       Session TF-MoP

Paper TF-MoP8
Characteristics of CuInSe@sub 2@ Thin Films Prepared in Different Selenization Pressures

Monday, November 2, 1998, 5:30 pm, Room Hall A

Session: Thin Films Poster Session
Presenter: S.D. Kim, Seoul National University, Korea
Authors: S.D. Kim, Seoul National University, Korea
C.H. Chung, Seoul National University, Korea
K.H. Yoon, Korea Institute of Energy Research, Korea
J.S. Song, Korea Institute of Energy Research, Korea
H.J. Kim, Seoul National University, Korea
Correspondent: Click to Email
CuInSe@sub 2@ based solar cell has great interest because CuInSe@sub 2@ has high absorption coefficient, suitable bandgap energy, good thermal stability, and good lattice match with window layers such as CdS, Cd(Zn)S. Its conversion efficiency has been reached above 15%. The selenization method has been known as an excellent technique to acquire low cost and high efficiency CuInSe@sub 2@ thin films. The effects of chamber pressure during selenization of Cu-In alloy layers on the optical, electrical and structural properties of CuInSe@sub 2@ films were investigated. The uniform Cu-In alloy layers could be reproducibly deposited on the glass substrate by dc co-sputtering method. The two atmospheres, Ar atmosphere at 1 atm and in vacuum of 10 mTorr, were chosen for the selenization of Cu-In layers. The properties of all films were analyzed by XRD, SEM, EDX, four point probe, Raman spectroscopy and photoluminescence. Cu-In precursors consisted of two phases, CuIn@sub 2@ and Cu@sub 11@In@sub 9@, and the amount of Cu@sub 11@In@sub 9@ phase increased with varying the composition from In-rich to Cu-rich. Less compounds of Cu-Se and In-Se were observed during the early stage of selenization and also CuInSe@sub 2@ single phase was more easily formed in vacuum than at atmospheric pressure. Therefore, CuInSe@sub 2@ films selenized in vacuum showed large grain size, smooth surface, dense microstructure, high Raman peak intensity and no secondary phases with near-stoichiometric composition. Since CuInSe@sub 2@ films selenized in vacuum could hardly release the intrinsic stress due to dense structure, Raman peak of 173 cm@super -1@, A1 mode of CuInSe@sub 2@ charcopyrite phase, shifted to higher frequency and had a broad full width of half maximum.