本征缺陷对δ-InSe光电性质的影响  

The Impact of Intrinsic Defects on the Optical and Electrical Properties ofδ-InSe

作　　者：苗瑞霞 张德栋 谢妙春 王业飞 杨小峰 MIAO Ruixia;ZHANG Dedong;XIE Miaochun;WANG Yefei;YANG Xiaofeng(College of Electronic Engineering,Xi’an University of Posts&Telecommunications,Xi’an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,西安710121

出　　处：《材料导报》2024年第23期7-13,共7页Materials Reports

基　　金：国家自然科学基金(51302215,62105260,12004303)。

摘　　要：作为一种典型的二维层状材料,二维InSe由于其独特的电学特性和较宽的带隙可调节范围,在新型二维电子和光电器件中具有广阔的应用前景。通过全局结构搜索和第一性原理计算发现的δ-InSe结构比已知的InSe结构具有更宽的带隙变化范围和更高的载流子迁移率。然而有关本征缺陷对δ-InSe电学和光学性质的研究尚未开展。本工作基于密度泛函理论的第一性原理,研究了δ-InSe结构中的本征缺陷对其光电性质的影响。结果表明:硒间隙缺陷Se i在富In和富Se的情况下都具有最小的形成能,是单层δ-InSe中最主要的缺陷。在施主类缺陷中,铟间隙缺陷In i作为浅能级缺陷,能够引起δ-InSe中n型导电特性,而受主类缺陷均为深能级缺陷,很难引起δ-InSe的p型导电特性。硒单空位缺陷V Se1、铟双空位缺陷V In2、硒双空位缺陷V Se2和铟间隙缺陷In i的引入能够使δ-InSe复介电函数的虚部和光吸收系数向低能区偏移,增强在可见光区域的光吸收强度,并对红外光区也产生了一定的吸收效应。此外,随着空位缺陷浓度的增加,缺陷能级数量变多,电子跃迁所需要的能量减少,吸收光谱发生红移。本研究有助于理解δ-InSe的缺陷性质,为δ-InSe的制备提供一定的理论指导,有助于推动δ-InSe在光电器件中的应用。As a typical two-dimensional layered material,InSe has broad prospects in new two-dimensional electronic and optoelectronic devices due to its unique electrical properties and wide range of adjustable bandgaps.Theδ-InSe structure discovered through global structural search and first-principles calculations has a wider bandgap variation range and higher carrier mobility compared to the known InSe structure.However,there is no research on the effects of intrinsic defects on the electrical and optical properties ofδ-InSe.Based on first-principles density functional theory,here studied the impact of intrinsic defects on the optical and electrical properties ofδ-InSe.The results showed that:the selenium interstitial defect has the smallest formation energy in both In-rich and Se-rich conditions,and is the main defect in single-layerδ-InSe.Among the donor-type defects,the indium interstitial defect Ini is a shallow-level defect that can cause n-type conductive behavior inδ-InSe,while the acceptor-type defects are deep-level defects that are difficult to cause p-type conductive behavior inδ-InSe.The introduction of selenium single vacancy defect V Se1,indium double vacancy defect V In2,selenium double vacancy defect V Se2,and indium interstitial defect In i can shift the imaginary part of the complex dielectric function and the optical absorption coefficient towards the lower energy region,enhance the optical absorption intensity in the visible light region,and also produce a certain absorption effect in the infrared light region.In addition,with the increase of vacancy defect concentration,the number of defect energy levels increases,and the energy required for electron transition decreases,resulting in a red shift of the absorption spectrum.This work will help to understand the defect properties ofδ-InSe,provide theoretical guidance for the preparation ofδ-InSe,and promote the application ofδ-InSe in optoelectronic devices.

关 键 词：第一性原理 本征缺陷 形成能 电学性质 光学性质 

分 类 号：O469[理学—凝聚态物理]