Acta Chim. Sinica ›› 2016, Vol. 74 ›› Issue (12): 1003-1008.DOI: 10.6023/A16080437 Previous Articles     Next Articles

Special Issue: 聚集诱导发光



赵兹罡, 鲁效庆, 李可, 魏淑贤, 刘学锋, 牛恺, 郭文跃   

  1. 中国石油大学(华东) 理学院 山东青岛 266580
  • 投稿日期:2016-08-26 发布日期:2016-10-20
  • 通讯作者: 鲁效庆
  • 基金资助:


First-Principles Theory Investigation on Structural and Photoelectronic Properties of Perovskites:Trigonal versus Hexagonal HC(NH2)2PbI3

Zhao Zigang, Lu Xiaoqing, Li Ke, Wei Shuxian, Liu Xuefeng, Niu Kai, Guo Wenyue   

  1. College of Science, China University of Petroleum, Qingdao 266580, China
  • Received:2016-08-26 Published:2016-10-20
  • Supported by:

    Project supported by the National Natural Science Foundation of China (21303266), the Fundamental Research Funds for the Central Universities (15CX05050A, 15CX08010A, and 14CX02214A), and Postgraduate's Innovation Project (YCXJ2016084).

Formamidinium lead halide perovskite FAPbI3(FA=HC(NH2)2+) has drawn wide attention as efficient photoelectronic conversion material.First-principles calculations were performed by using the Vienna ab initio simulation package (VASP) based on density functional theory.The structure configuration,electronic property,absorption spectrum,and bonding energy were analyzed to elucidate the structural and photoelectronic properties of trigonal and hexagonal FAPbI3 perovskites.Results showed that the crystal deformation from trigonal to hexagonal crystal would distort the PbI3 framework,change the covalent/ionic Pb-I bonds,and eventually alter the semiconductor bandgaps.The trigonal and hexagonal FAPbI3 perovskites are both direct-bandgap semiconductors.The direct-bandgap nature of trigonal crystal locates at Z (0,0,0.5) symmetry point with the ideal bandgap of ca.1.50 eV;the direct-bandgap nature of hexagonal crystal locates at Γ(0,0,0) symmetry point with the wide bandgap of ca.2.50 eV.For the both crystals,the main contributions to VBM (valence band maximum) are I 5p orbitals with a little overlapping of Pb 6s orbitals,and the main components of CBM (conduction band minimum) are Pb 6p orbitals.The FA cations do not directly participate into the electron transition process,just acting as charge donors to supply PbI3 framework with more than 0.7 e.There exists both covalent and ionic interactions between Pb and I ions.Compared with the hexagonal crystal,the trigonal FAPbI3 possesses smaller electron and hole effective masses.It exhibits dramatic red shifted absorption spectrum and a better absorption efficiency than hexagonal FAPbI3 and tetragonal MAPbI3(MA=CH3NH3+) perovskites.Bonding energy analyses showed that the hexagonal FAPbI3 was more stable than the trigonal crystal,and interaction between FA and PbI3 framework was stronger than that between MA and PbI3 framework.Our results could provide theoretical guidance for the experimental design and synthesis of FAPbI3 perovskite solar cells.

Key words: HC(NH2)2PbI3 perovskite, first-principles theory, crystal deformation, photoelectronic property, bonding energy