中国物理B ›› 2016, Vol. 25 ›› Issue (12): 127101-127101.doi: 10.1088/1674-1056/25/12/127101

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

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

Zong-Yan Zhao(赵宗彦), Wen Yang(杨雯), Pei-Zhi Yang(杨培志)   

  1. 1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
    2. Yunnan Key Laboratory of Micro/Nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming 650504, China;
    3. Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials(Ministry of Education), Yunnan Normal University, Kunming 650092, China
  • 收稿日期:2016-04-25 修回日期:2016-08-10 出版日期:2016-12-05 发布日期:2016-12-05
  • 通讯作者: Zong-Yan Zhao E-mail:zzy@kmust.edu.cn
  • 基金资助:

    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), and the National Natural Science Foundation of China (Grant No. U1037604).

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

Zong-Yan Zhao(赵宗彦)1,2, Wen Yang(杨雯)3, Pei-Zhi Yang(杨培志)3   

  1. 1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
    2. Yunnan Key Laboratory of Micro/Nano Materials & Technology, School of Materials Science and Engineering, Yunnan University, Kunming 650504, China;
    3. Key Laboratory of Advanced Technique & Preparation for Renewable Energy Materials(Ministry of Education), Yunnan Normal University, Kunming 650092, China
  • Received:2016-04-25 Revised:2016-08-10 Online:2016-12-05 Published:2016-12-05
  • Contact: Zong-Yan Zhao E-mail:zzy@kmust.edu.cn
  • Supported by:

    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), and the National Natural Science Foundation of China (Grant No. U1037604).

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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 DFT+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 O 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 cells in the future.

关键词: SiGe alloys, O doping, electronic structure, density functional theory (DFT) calculations

Abstract:

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 DFT+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 O 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 cells in the future.

Key words: SiGe alloys, O doping, electronic structure, density functional theory (DFT) calculations

中图分类号:  (Electron density of states and band structure of crystalline solids)

  • 71.20.-b
71.20.Nr (Semiconductor compounds) 81.05.Hd (Other semiconductors) 82.20.Wt (Computational modeling; simulation)