Electronic Structure and Optical Properties of 伪-CH3NH3PbBr3 Perovskite Single Crystal

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• 作者：Ji-Sang Park ; Sukgeun Choi ; Yong Yan ; Ye Yang ; Joseph M. Luther ; Su-Huai Wei ; Philip Parilla ; Kai Zhu
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：November 5, 2015
• 年：2015
• 卷：6
• 期：21
• 页码：4304-4308
• 全文大小：391K
• ISSN：1948-7185

文摘

The electronic structure and related optical properties of an emerging thin-film photovoltaic material CH₃NH₃PbBr₃ are studied. A block-shaped 伪-phase CH₃NH₃PbBr₃ single crystal with the natural 鉄?00鉄?surface is synthesized solvothermally. The room-temperature dielectric function 蔚 = 蔚₁ + i蔚₂ spectrum of CH₃NH₃PbBr₃ is determined by spectroscopic ellipsometry from 0.73 to 6.45 eV. Data are modeled with a series of Tauc鈥揕orentz oscillators, which show the absorption edge with a strong excitonic transition at 鈭?.3 eV and several above-bandgap optical structures associated with the electronic interband transitions. The energy band structure and 蔚 data of CH₃NH₃PbBr₃ for the CH₃NH₃⁺ molecules oriented in the 鉄?11鉄?and 鉄?00鉄?directions are obtained from first-principles calculations. The overall shape of 蔚 data shows a qualitatively good agreement with experimental results. Electronic origins of major optical structures are discussed.