Crystalline Engineering Toward Large-Scale High-Efficiency Printable Cu(In,Ga)Se2 Thin Film Solar Cells on Flexible Substrate by Femtosecond Laser Annealing Process

Shih-Chen Chen; Nian-Zu She; Kaung-Hsiung Wu; Yu-Ze Chen; Wei-Sheng Lin; Jia-Xing Li; Fang-I Lai; Jenh-Yih Juang; Chih Wei Luo; Lung-Teng Cheng; Tung-Po Hsieh; Hao-Chung Kuo; Yu-Lun Chueh

doi:10.1021/acsami.7b00082

Crystalline Engineering Toward Large-Scale High-Efficiency Printable Cu(In,Ga)Se₂ Thin Film Solar Cells on Flexible Substrate by Femtosecond Laser Annealing Process

ACS Appl Mater Interfaces. 2017 Apr 26;9(16):14006-14012. doi: 10.1021/acsami.7b00082. Epub 2017 Apr 11.

Authors

Affiliations

¹ Department of Materials Science and Engineering, National Tsing Hua University , Hsinchu 30013, Taiwan, ROC.
² Compound Semiconductor Solar Cell Department, Next Generation Solar Cell Division, Green Energy and Environment Research Laboratories, Industrial Technology Research Institute , Hsinchu 31040, Taiwan, ROC.
³ Department of Photonics Engineering, Yuan-Ze University , Taoyuan 32003, Taiwan, ROC.
⁴ School of Material Science and Engineering, State Key Laboratory of Advanced Processing and Recycling of Non-Ferrous Metals, Lanzhou University of Technology , Lanzhou City 730050, Gansu Province, P. R. China.
⁵ Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China , Chengdu 611731, P. R. China.
⁶ Department of Physics, National Sun Yat-Sen University , Kaohsiung, 80424, Taiwan, ROC.

PMID: 28281352
DOI: 10.1021/acsami.7b00082

Abstract

Ink-printing method emerges as a viable way for manufacturing large-scale flexible Cu(In,Ga)Se₂ (CIGS) thin film photovoltaic (TFPV) devices owing to its potential for the rapid process, mass production, and low-cost nonvacuum device fabrication. Here, we brought the femtosecond laser annealing (fs-LA) process into the ink-printing CIGS thin film preparation. The effects of fs-LA treatment on the structural and optoelectronic properties of the ink-printing CIGS thin films were systematically investigated. It was observed that, while the film surface morphology remained essentially unchanged under superheating, the quality of crystallinity was significantly enhanced after the fs-LA treatment. Moreover, a better stoichiometric composition was achieved with an optimized laser scanning rate of the laser beam, presumably due to the much reduced indium segregation phenomena, which is believed to be beneficial in decreasing the defect states of In_Se, V_Se, and In_Cu. Consequently, the shunt leakage current and recombination centers were both greatly decreased, resulting in a near 20% enhancement in photovoltaic conversion efficiency.

Keywords: Cu(In,Ga)Se2; flexible; ink-printing; laser annealing; solar cell.