Electronic Structure of CH3NH3PbX3 Perovskites: Dependence on the Halide Moiety

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• 作者：Rebecka Lindblad ; Naresh K. Jena ; Bertrand Philippe ; Johan Oscarsson ; Dongqin Bi ; Andreas Lindblad ; Suman Mandal ; Banabir Pal ; D. D. Sarma ; Olof Karis ; Hans Siegbahn ; Erik M. J. Johansson ; Michael Odelius ; H氓kan Rensmo
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：January 29, 2015
• 年：2015
• 卷：119
• 期：4
• 页码：1818-1825
• 全文大小：388K
• ISSN：1932-7455

文摘

A combination of measurements using photoelectron spectroscopy and calculations using density functional theory (DFT) was applied to compare the detailed electronic structure of the organolead halide perovskites CH₃NH₃PbI₃ and CH₃NH₃PbBr₃. These perovskite materials are used to absorb light in mesoscopic and planar heterojunction solar cells. The Pb 4f core level is investigated to get insight into the chemistry of the two materials. Valence level measurments are also included showing a shift of the valence band edges where there is a higher binding energy of the edge for the CH₃NH₃PbBr₃ perovskite. These changes are supported by the theoretical calculations which indicate that the differences in electronic structure are mainly caused by the nature of the halide ion rather than structural differences. The combination of photoelectron spectroscopy measurements and electronic structure calculations is essential to disentangle how the valence band edge in organolead halide perovskites is governed by the intrinsic difference in energy levels of the halide ions from the influence of chemical bonding.