Infrared Spectroscopic Study of Vibrational Modes in Methylammonium Lead Halide Perovskites
Infrared Spectroscopic Study of Vibrational Modes in Methylammonium Lead Halide Perovskites
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DOI：
10.1021/acs.jpclett.5b01309
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发表时间：
2015-08-06
影响因子：
5.7
通讯作者：
Lovrincic, Robert
中科院分区：
文献类型：
--
作者：
Glaser, Tobias;Mueller, Christian;Lovrincic, Robert
有机阳离子及其与无机晶格的相互作用是有机金属卤化物钙钛矿的特殊光电性能的基础。本文报道了室温下甲基铵卤化铅钙钛矿（CH_3NH_3Pb（I/Br/Cl）（3））薄膜和单晶的高质量红外光谱测量结果，由此导出了所研究光谱范围内的介电函数。在真空中的自由甲基铵阳离子的电子结构计算的比较允许一个详细的峰归属。我们分析了不同卤化物之间的振动峰位置的移动，并推断有机部分和周围的无机笼之间的相互作用的程度。NH3+伸缩振动的位置指向所有三种钙钛矿的甲基铵和卤化物之间的显著氢键。
The organic cation and its interplay with the inorganic lattice underlie the exceptional optoelectronic properties of organo-metallic halide perovskites. Herein we report high-quality infrared spectroscopic measurements of methylammonium lead halide perovskite (CH3NH3Pb(I/Br/Cl)(3)) films and single crystals at room temperature, from which the dielectric function in the investigated spectral range is derived. Comparison with electronic structure calculations in vacuum of the free methylammonium cation allows for a detailed peak assignment. We analyze the shifts of the vibrational peak positions between the different halides and infer the extent of interaction between organic moiety and the surrounding inorganic cage. The positions of the NH3+ stretching vibrations point to significant hydrogen bonding between the methylammonium and the halides for all three perovskites.