Key Laboratory of Inorganic Functional Material and Device, CAS, Shanghai Institute of Ceramics, Chinese Academy of Sciences
中国科学院无机功能材料与器件重点实验室 

First-principles study of the structural and the electronic properties of the lead-halide-based inorganic-organic perovskites (CH₃NH₃) PbX₃ and CsPbX₃ (X= Cl, Br, I)

Prof. Chul Hong Park

Department of Physics Education

Pusan National University

Gumjung, Pusan 46241, Korea

时间：2017年8月24日（星期四）下午14:00

　　地点： 4 号楼 14楼第一会议室

　　联系人：郑嘹赢 研究员

李国荣　研究员

欢迎各位老师同学光临!

First-principles study of the structural and the electronic properties of the lead-halide-based inorganic-organic perovskites (CH3NH3) PbX3 and CsPbX3 (X= Cl, Br, I)

Chul Hong Park

Pusan National University, Busan, Korea

Abstract

In this talk, the basic understanding of the inorganic-organic perovskite solar cell materials and the applications will be discussed. The structural and the electronic properties of the lead-halide based inorganic-organic perovskites (CH₃NH₃)PbX₃ (where X = Cl, Br and I) and inorganic perovskite CsPbX₃ will be discussed based on the first-principles pseudopotential calculations. The electronic structures of both kinds of perovskites are found to be similar around the band edges. The electronic levels from the organic molecules are located deeply within the valence and conduction-bands, indicating that the effects of the organic molecule on the electronic and the optical properties are weak. The valence-band maximum is characterized as an antibonding hybrid state of the Pb-s and the X-p orbitals in the Pb-X chains. The conduction-band minimum is characterized as a non-bonding hybrid state of the Pb-p and the X-p orbitals. The band gaps are found to red shift with pressure. We examined the electronic structures of the two-dimensional layered structures of the perovskites. The band gap decreased due to the confinement effect of carriers with increasing number of perovskite layers.