title: Observation of unusual optical transitions in thin-film Cu(In,Ga)Se2 solar cells.
abstract: In this paper, we examine photoluminescence spectra of Cu(In,Ga)Se(2) (CIGS) via temperature-dependent and power-dependent photoluminescence (PL). Donor-acceptor pair (DAP) transition, near-band-edge transition were identified by their activation energies. S-shaped displacement of peak position was observed and was attributed to carrier confinement caused by potential fluctuation. This coincides well with the obtained activation energy at low temperature. We also present a model for transition from V(Se) to V(In) and to V(Cu) which illustrates competing mechanisms between DAPs recombinations.
authors.affiliation: Department of Electro-Physics, National Chiao-Tung University, Hsinchu, Taiwan.
authors.forename: Yu-Kuang
authors.initials: YK
authors.lastname: Liao
authors.forename: Shou-Yi
authors.initials: SY
authors.lastname: Kuo
authors.forename: Woei-Tyng
authors.initials: WT
authors.lastname: Lin
authors.forename: Fang-I
authors.initials: FI
authors.lastname: Lai
authors.forename: Dan-Hua
authors.initials: DH
authors.lastname: Hsieh
authors.forename: Min-An
authors.initials: MA
authors.lastname: Tsai
authors.forename: Shih-Chen
authors.initials: SC
authors.lastname: Chen
authors.forename: Ding-Wen
authors.initials: DW
authors.lastname: Chiou
authors.forename: Jen-Chuang
authors.initials: JC
authors.lastname: Chang
authors.forename: Kaung-Hsiung
authors.initials: KH
authors.lastname: Wu
authors.forename: Shun-Jen
authors.initials: SJ
authors.lastname: Cheng
authors.forename: Hao-Chung
authors.initials: HC
authors.lastname: Kuo