CH3NH3PbI3和CH3NH3MnI3的电子结构和光学性质研究

采用第一性原理计算,研究了有机金属卤化物钙钛矿CH₃NH₃PbI₃和CH₃NH₃MnI₃的电子结构、磁性和光吸收。CH₃NH₃PbI₃和CH₃NH₃MnI₃都是具有直接带隙半导体,CH₃NH₃MnI₃磁基态为G型反铁磁序(G-AFM)。CH₃NH₃MnI₃在G-AFM状态下的带隙值为1.668 eV;当系统处于FM态时,多数自旋通道的带隙为0.696 eV,少数自旋通道的带隙为2.148 eV。结果表明,具有FM态的CH₃NH₃MnI₃的光激发电子将迅速熔化局域磁序。最后计算了CH₃NH₃PbI₃和CH₃NH₃MnI₃的光学特性,结果表明具有铁磁态的CH₃NH₃MnI₃(FM)表现出较强的红外光吸收。

Study on Electronic Structure and Optical Property of CH_3NH_3XI_3(X=Pb,Mn)

Using the first principles calculations,the electronic structure and optical absorption of the organometal halide perovskite CH₃NH₃PbI₃and CH₃NH₃MnI₃are studied.CH₃NH₃PbI₃and CH₃NH₃MnI₃are both semiconductors with direct band gap.The magnetic ground states of CH₃NH₃MnI₃are the G-type antiferromagnetic order(AFM).The band gap of the CH₃NH₃MnI₃(GAFM)is about 1.668 eV.For CH₃NH₃MnI₃(FM),the band gap value of the CH₃NH₃MnI₃(FM)in the spin majority channel is about 0.696 eV,and the band gap in the spin minority channel is about2.148 eV,which proves that photo-excited electrons of CH₃NH₃MnI₃(FM)will rapidly melt the local magnetic order.Finally,the optical properties of CH₃NH₃PbI₃and CH₃NH₃MnI₃are calculated,and the results show that the CH₃NH₃MnI₃(FM)has strong infrared light absorption.