After CdIn2S4 films grown by hot-wall epitaxy method were annealed in Cd-, S- and In- atmospheres, the point defects were investigated by using the low photoluminescence experiment. In the as-grown CdIn2S4 films, the free excitons corresponding to the light hole and the heavy hole were observed, and their splitting gap was 8.2 MeV. The gap was associated with the strain caused by the lattice mismatch between the substrate and the film in the heterojunction growth. By means of thermal annealing in various atmospheres, the (D°, X) emission was observed to originate from the VS or Cdint. From this emission, the ED value of the donor impurity level was extracted to 0.1950eV. Also, the emission between the free electrons and the acceptor holes became a dominant peak after S atmosphere treatment, and the EA value of the acceptor level was found to be 0.2371eV. Thus, the origin of the acceptor hole emission was related to VCd or Sint. These photoluminescence results led to the confirmation that CdIn2S4:S was converted into the optical p-type. In addition, the origin of the donor–acceptor pair emissions was caused by the recombination between donors such as VS or Cdint and acceptors such as VCd or Sint. Based upon these photoluminescence results, a new energy-level diagram of the recombination process in CdIn2S4 was mapped out.

Point Defect Study from Low Photoluminescence of the CdIn2S4 Films Grown by Hot Wall Epitaxy Method. S.H.You, K.J.Hong, T.S.Jeong, C.J.Youn, J.S.Park, B.J.Lee, J.W.Jeong: Journal of Crystal Growth, 2004, 271[3-4], 391-7