title: In-Situ Probing Plasmonic Energy Transfer in Cu(In, Ga)Se2 Solar Cells by Ultrabroadband Femtosecond Pump-Probe Spectroscopy.
abstract: In this work, we demonstrated a viable experimental scheme for in-situ probing the effects of Au nanoparticles (NPs) incorporation on plasmonic energy transfer in Cu(In, Ga)Se2 (CIGS) solar cells by elaborately analyzing the lifetimes and zero moment for hot carrier relaxation with ultrabroadband femtosecond pump-probe spectroscopy. The signals of enhanced photobleach (PB) and waned photoinduced absorption (PIA) attributable to surface plasmon resonance (SPR) of Au NPs were in-situ probed in transient differential absorption spectra. The results suggested that substantial carriers can be excited from ground state to lower excitation energy levels, which can reach thermalization much faster with the existence of SPR. Thus, direct electron transfer (DET) could be implemented to enhance the photocurrent of CIGS solar cells. Furthermore, based on the extracted hot carrier lifetimes, it was confirmed that the improved electrical transport might have been resulted primarily from the reduction in the surface recombination of photoinduced carriers through enhanced local electromagnetic field (LEMF). Finally, theoretical calculation for resonant energy transfer (RET)-induced enhancement in the probability of exciting electron-hole pairs was conducted and the results agreed well with the enhanced PB peak of transient differential absorption in plasmonic CIGS film. These results indicate that plasmonic energy transfer is a viable approach to boost high-efficiency CIGS solar cells.
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Shih-Chen
authors.initials: SC
authors.lastname: Chen
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Kaung-Hsiung
authors.initials: KH
authors.lastname: Wu
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Jia-Xing
authors.initials: JX
authors.lastname: Li
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yabushita
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Shih-Han
authors.initials: SH
authors.lastname: Tang
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Chih Wei
authors.initials: CW
authors.lastname: Luo
authors.affiliation: Department of Electrophysics, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Jenh-Yih
authors.initials: JY
authors.lastname: Juang
authors.affiliation: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao-Tung University, Hsinchu 30010, Taiwan.
authors.forename: Hao-Chung
authors.initials: HC
authors.lastname: Kuo
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