title: Light-soaking effects and capacitance profiling in Cu(In,Ga)Se2thin-film solar cells with chemical-bath-deposited ZnS buffer layers.
abstract: We fabricated Cu(In,Ga)Se2(CIGS) solar cells with chemical-bath deposited (CBD) ZnS buffer layers with different deposition times. The conversion efficiency and the fill factor of the CIGS solar cells reveal a strong dependence on the deposition time of CBD-ZnS films. In order to understand the detailed relationship between the heterojunction structure and the electronic properties of CIGS solar cells with different deposition times of CBD-ZnS films, capacitance-voltage (C-V) profiling measurements with additional laser illumination were performed. The light-soaking effects on CIGS solar cells with a CBD-ZnS buffer layer were investigated in detail using current density-voltage (J-V) and C-V measurements with several different lasers with different emission wavelengths. After light-soaking, the conversion efficiency changed significantly and the double diode feature in J-V curves disappeared. We explain that the major reason for the improvement of efficiency by light-soaking is due to the fact that negatively charged and highly defective vacancies in the CIGS absorber near the interface of CBD-ZnS/CIGS were formed and became neutral due to carriers generated by ultra-violet absorption in the buffer layer.
authors.affiliation: Kongju National University, 182 Shingwan-dong, Gongju-si, Chungnam 32588, Republic of Korea. jh-song@kongju.ac.kr and Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
authors.forename: Hye-Jung
authors.initials: HJ
authors.lastname: Yu
authors.affiliation: Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
authors.forename: Woo-Jung
authors.initials: WJ
authors.lastname: Lee
authors.affiliation: Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
authors.forename: Jae-Hyung
authors.initials: JH
authors.lastname: Wi
authors.affiliation: Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
authors.forename: Dae-Hyung
authors.initials: DH
authors.lastname: Cho
authors.affiliation: Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea.
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Han
authors.affiliation: Electronics and Telecommunications Research Institute (ETRI), 218 Gajeong-ro, Yuseong-gu, Daejeon 34129, Republic of Korea and Korea University of Science and Technology (UST), 217 Gajeong-ro, Yuseong-gu, Daejeon 34113, Republic of Korea.
authors.forename: Yong-Duck
authors.initials: YD
authors.lastname: Chung
authors.affiliation: Kongju National University, 182 Shingwan-dong, Gongju-si, Chungnam 32588, Republic of Korea. jh-song@kongju.ac.kr.
authors.forename: Tae-Soo
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Kongju National University, 182 Shingwan-dong, Gongju-si, Chungnam 32588, Republic of Korea. jh-song@kongju.ac.kr.
authors.forename: Jung-Hoon
authors.initials: JH
authors.lastname: Song