標題: Femtosecond Transient Absorption Spectra and Dynamics of Carrier Relaxation of Tin Perovskites in the Absence and Presence of Additives
作者: Narra, Sudhakar
Jokar, Efat
Pearce, Orion
Lin, Chia-Yi
Fathi, Amir
Diau, Eric Wei-Guang
交大名義發表
應用化學系
應用化學系分子科學碩博班
National Chiao Tung University
Department of Applied Chemistry
Institute of Molecular science
公開日期: 16-Jul-2020
摘要: The effects of additives SnF2 (10%) and EDAI(2) (1%) on the dynamics of carrier relaxation of formamidinium tin triiodide (FASnI(3)) perovskite were studied using femtosecond transient absorption spectra (TAS) with excitation at 600 and 870 nm. The TAS were analyzed according to a parallel sequential kinetic model with a global fit through singular-value decomposition. For excitation at 600 nm, two relaxation paths were found: one involved hot and cold carriers in the bulk state undergoing shallow bulk-defect-mediated charge recombination; the other involved trap carriers in the surface state undergoing deep surface-defect-mediated charge recombination. For excitation at 870 nm, only cold carriers were subjected to the bulk-state relaxation channel. Our spectral results indicate significant effects of the additives on retarding charge recombination in both bulk and surface states as well as decreasing the bandgap renormalization energy, the bandwidth of the photobleaching (PB) band, and the Stokes shift between the PB and photoluminescence bands, explaining how the device performance of FASnI(3) solar cells became enhanced in the presence of SnF2 and EDAI(2).
URI: http://dx.doi.org/10.1021/acs.jpclett.0c01589
http://hdl.handle.net/11536/155159
ISSN: 1948-7185
DOI: 10.1021/acs.jpclett.0c01589
期刊: JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Volume: 11
Issue: 14
起始頁: 5699
結束頁: 5704
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