Wilks Regan G, Erbing Axel, Sadoughi Golnaz, Starr David E, Handick Evelyn, Meyer Frank, Benkert Andreas, Iannuzzi Marcella, Hauschild Dirk, Yang Wanli, Blum Monika, Weinhardt Lothar, Heske Clemens, Snaith Henry J, Odelius Michael, Bär Marcus
Renewable Energy, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), 14109 Berlin, Germany.
Department of Physics, Stockholm University, AlbaNova University Center, 106 91 Stockholm, Sweden.
J Phys Chem Lett. 2021 Apr 29;12(16):3885-3890. doi: 10.1021/acs.jpclett.1c00745. Epub 2021 Apr 15.
The organic component (methylammonium) of CHNHPbICl-based perovskites shows electronic hybridization with the inorganic framework via H-bonding between N and I sites. Femtosecond dynamics induced by core excitation are shown to strongly influence the measured X-ray emission spectra and the resonant inelastic soft X-ray scattering of the organic components. The N core excitation leads to a greatly increased N-H bond length that modifies and strengthens the interaction with the inorganic framework compared to that in the ground state. The study indicates that excited-state dynamics must be accounted for in spectroscopic studies of this perovskite solar cell material, and the organic-inorganic hybridization interaction suggests new avenues for probing the electronic structure of this class of materials. It is incidentally shown that beam damage to the methylamine component can be avoided by moving the sample under the soft X-ray beam to minimize exposure and that this procedure is necessary to prevent the creation of experimental artifacts.
基于CHNHPbICl的钙钛矿的有机成分（甲铵）通过N和I位点之间的氢键与无机骨架表现出电子杂化。由核心激发诱导的飞秒动力学被证明会强烈影响所测量的有机成分的X射线发射光谱和共振非弹性软X射线散射。与基态相比，N核心激发导致N-H键长度大幅增加，这改变并加强了与无机骨架的相互作用。该研究表明，在这种钙钛矿太阳能电池材料的光谱研究中必须考虑激发态动力学，并且有机-无机杂化相互作用为探测这类材料的电子结构提供了新途径。顺便指出，通过在软X射线束下移动样品以尽量减少曝光，可以避免对甲胺成分的束损伤，并且该程序对于防止产生实验假象是必要的。
