Peculiar band geometry induced giant shift current in ferroelectric SnTe monolayer  

作　　者：Gan Jin Lixin He 

机构地区：[1]Key Laboratory of Quantum Information,University of Science and Technology of China,Hefei 230026,China [2]Hefei National Laboratory,University of Science and Technology of China,Hefei,Anhui 230088,China [3]Institute of Artificial Intelligence,Hefei Comprehensive National Science Center,Hefei,Anhui 230026,China

出　　处：《npj Computational Materials》2024年第1期3011-3016,共6页计算材料学(英文)

基　　金：funded by the National Natural Science Foundation of China,Grant Number 12134012;the Innovation Program for Quantum Science and Technology,Grant Number 2021ZD0301200.

摘　　要：The bulk photovoltaic effect(BPVE)occurs when homogeneous noncentrosymmetric materials generate photocurrent or photovoltage under illumination.The intrinsic contribution to this effect is known as the shift current effect.We calculate the shift current conductivities of the ferroelectric SnTe monolayer using first-principles methods.Our results reveal a giant shift-current conductivity near the valley points in the SnTe monolayer.More remarkably,the linear optical absorption coefficient at this energy is very small,resulting in an enormous Glass coefficient that is four orders of magnitude larger than that of BaTiO_(3).To understand these giant shift-current effects,we employ a three-band model and find that they arise from the nontrivial energy band geometries near the valley points,where the shift-vector diverges.This serves as a prominent example highlighting the crucial role of band geometry in determining the fundamental properties of solids.

关 键 词：effect MONOLAYER FERROELECTRIC 

分 类 号：O47[理学—半导体物理]