title: Enhanced Conversion Efficiency of Cu(In,Ga)Se2 Solar Cells via Electrochemical Passivation Treatment.
abstract: Defect control in Cu(In,Ga)Se2 (CIGS) materials, no matter what the defect type or density, is a significant issue, correlating directly to PV performance. These defects act as recombination centers and can be briefly categorized into interface recombination and Shockley-Read-Hall (SRH) recombination, both of which can lead to reduced PV performance. Here, we introduce an electrochemical passivation treatment for CIGS films that can lower the oxygen concentration at the CIGS surface as observed by X-ray photoelectron spectrometer analysis. Temperature-dependent J-V characteristics of CIGS solar cells reveal that interface recombination is suppressed and an improved rollover condition can be achieved following our electrochemical treatment. As a result, the surface defects are passivated, and the power conversion efficiency performance of the solar cell devices can be enhanced from 4.73 to 7.75%.
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Hung-Wei
authors.initials: HW
authors.lastname: Tsai
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.|Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu, Sichuan 610051, PR China.
authors.forename: Stuart R
authors.initials: SR
authors.lastname: Thomas
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Chia-Wei
authors.initials: CW
authors.lastname: Chen
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Yi-Chung
authors.initials: YC
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Hsu-Sheng
authors.initials: HS
authors.lastname: Tsai
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Yu-Ting
authors.initials: YT
authors.lastname: Yen
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Hsu
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Wen-Chi
authors.initials: WC
authors.lastname: Tsai
authors.affiliation: Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu, Sichuan 610051, PR China.
authors.forename: Zhiming M
authors.initials: ZM
authors.lastname: Wang
authors.affiliation: Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan.
authors.forename: Yu-Lun
authors.initials: YL
authors.lastname: Chueh
keywords: CIGS solar cells; EA activation energy; electrochemical passivation; rollover condition; temperature-dependent J−V characteristics