Electronic structure of O-doped SiGe calculated by DFT+U method  

作　　者：赵宗彦 杨雯 杨培志 

机构地区：[1]Faculty of Materials Science and Engineering,Kunming University of Science and Technology [2]Yunnan Key Laboratory of Micro/Nano Materials & Technology,School of Materials Science and Engineering,Yunnan University [3]Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials (Ministry of Education),Yunnan Normal University

出　　处：《Chinese Physics B》2016年第12期377-389,共13页中国物理B（英文版）

基　　金：Project supported by the Natural Science Foundation of Yunnan Province,China(Grant No.2015FB123);the 18th Yunnan Province Young Academic and Technical Leaders Reserve Talent Project,China(Grant No.2015HB015);the National Natural Science Foundation of China(Grant No.U1037604)

摘　　要：To more in depth understand the doping effects of oxygen on SiGe alloys, both the micro-structure and properties of O-doped SiGe （including： bulk, （001） surface, and （110） surface） are calculated by DPT ＋ U method in the present work. The calculated results are as follows. （i） The （110） surface is the main exposing surface of SiGe, in which O impurity prefers to occupy the surface vacancy sites. （ii） For O interstitial doping on SiGe （110） surface, the existences of energy states caused by 0 doping in the band gap not only enhance the infrared light absorption, but also improve the behaviors of photo-generated carriers. （iii） The finding about decreased surface work function of O-doped SiGe （110） surface can confirm previous experimental observations. （iv） In all cases, O doing mainly induces the electronic structures near the band gap to vary, but is not directly involved in these variations. Therefore, these findings in the present work not only can provide further explanation and analysis for the corresponding underlying mechanism for some of the experimental findings reported in the literature, but also conduce to the development of μc-SiGe-based solar ceils in the future.To more in depth understand the doping effects of oxygen on SiGe alloys, both the micro-structure and properties of O-doped SiGe （including： bulk, （001） surface, and （110） surface） are calculated by DPT ＋ U method in the present work. The calculated results are as follows. （i） The （110） surface is the main exposing surface of SiGe, in which O impurity prefers to occupy the surface vacancy sites. （ii） For O interstitial doping on SiGe （110） surface, the existences of energy states caused by 0 doping in the band gap not only enhance the infrared light absorption, but also improve the behaviors of photo-generated carriers. （iii） The finding about decreased surface work function of O-doped SiGe （110） surface can confirm previous experimental observations. （iv） In all cases, O doing mainly induces the electronic structures near the band gap to vary, but is not directly involved in these variations. Therefore, these findings in the present work not only can provide further explanation and analysis for the corresponding underlying mechanism for some of the experimental findings reported in the literature, but also conduce to the development of μc-SiGe-based solar ceils in the future.

关 键 词：SiGe alloys 0 doping electronic structure density functional theory （DFT） calculations 

分 类 号：TM914.4[电气工程—电力电子与电力传动] TN304[电子电信—物理电子学]