https://scholars.lib.ntu.edu.tw/handle/123456789/547554
標題: | XPS evidence of degradation mechanism in CH 3 NH 3 PbI 3 hybrid perovskite | 作者: | Zhidkov, I.S. Poteryaev, A.I. Kukharenko, A.I. Finkelstein, L.D. Cholakh, S.O. Akbulatov, A.F. Troshin, P.A. Chueh, C.-C. Kurmaev, E.Z. CHU-CHEN CHUEH |
關鍵字: | hybrid halide perovskites; photovoltaics; XPS | 公開日期: | 2020 | 卷: | 32 | 期: | 9 | 來源出版物: | Journal of Physics Condensed Matter | 摘要: | In this study, we investigate the photo-/thermal degradation mechanism of hybrid perovskites by using x-ray photoelectron (XPS) valence band (VB) spectra coupling with density functional theory (DFT) calculations. Herein, CH3NH3PbI3 is respectively subjected to irradiation with visible light and annealing at an exposure of 0-1000 h. It is found from XPS survey spectra that, in both cases (irradiation and annealing), a decrease in the I:Pb ratio is observed with aging time, which unambiguously indicates the formation of PbI2 as the product of photo/thermal degradation. The comparison of the XPS VB spectra of irradiated and annealed perovskites with the DFT calculations of CH3NH3PbI3 and PbI2 compounds have showed a systematic decrease in the contribution of I-5p states, which allows us to determine the respective threshold for degradation, which is 500 h for light irradiation and 200 h for annealing. This discrepancy might be due to the fact that the relaxation of thermal excitations of the system is carried out only by the phonons (which are non-radiative physical processes) while the radiative processes occurred during the photoexcitation will elastically or inelastically divert part of the external energy from the system to reduce its impact on perovskite degradation. © 2019 IOP Publishing Ltd. |
URI: | https://www.scopus.com/inward/record.url?eid=2-s2.0-85077297673&partnerID=40&md5=630abf38ca59912e011848e5d6a85fdb https://scholars.lib.ntu.edu.tw/handle/123456789/547554 |
ISSN: | Zhidkov, I.S.;Poteryaev, A.I.;Kukharenko, A.I.;Finkelstein, L.D.;Cholakh, S.O.;Akbulatov, A.F.;Troshin, P.A.;Chueh, C.-C.;Kurmaev, E.Z. | DOI: | 10.1088/1361-648X/ab576f | SDG/關鍵字: | Annealing; Degradation; Density functional theory; Irradiation; Layered semiconductors; Light; Perovskite; Photodegradation; Photoelectron spectroscopy; X ray photoelectron spectroscopy; Degradation mechanism; Halide perovskites; Light irradiations; Photovoltaics; Radiative process; Thermal excitation; Valence band spectra; X-ray photoelectrons; Lead compounds |
顯示於: | 化學工程學系 |
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