中国物理B ›› 2017, Vol. 26 ›› Issue (10): 103101-103101.doi: 10.1088/1674-1056/26/10/103101

• ATOMIC AND MOLECULAR PHYSICS • 上一篇    下一篇

Correlation between electronic structure and energy band in Eu-doped CuInTe2 semiconductor compound with chalcopyrite structure

Tai Wang(王泰), Yong-Quan Guo(郭永权), Shuai Li(李帅)   

  1. School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
  • 收稿日期:2017-04-05 修回日期:2017-06-15 出版日期:2017-10-05 发布日期:2017-10-05
  • 通讯作者: Yong-Quan Guo E-mail:yqguo@ncepu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No.1 1274110).

Correlation between electronic structure and energy band in Eu-doped CuInTe2 semiconductor compound with chalcopyrite structure

Tai Wang(王泰), Yong-Quan Guo(郭永权), Shuai Li(李帅)   

  1. School of Energy Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
  • Received:2017-04-05 Revised:2017-06-15 Online:2017-10-05 Published:2017-10-05
  • Contact: Yong-Quan Guo E-mail:yqguo@ncepu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No.1 1274110).

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摘要： The Eu-doped Cu(In, Eu)Te2 semiconductors with chalcopyrite structures are promising materials for their applications in the absorption layer for thin-film solar cells due to their wider band-gaps and better optical properties than those of CuInTe2. In this paper, the Eu-doped CuInTe2 (CuIn1-xEuxTe2, x=0, 0.1, 0.2, 0.3) are studied systemically based on the empirical electron theory (EET). The studies cover crystal structures, bonding regularities, cohesive energies, energy levels, and valence electron structures. The theoretical values fit the experimental results very well. The physical mechanism of a broadened band-gap induced by Eu doping into CuInTe2 is the transitions between different hybridization energy levels induced by electron hopping between s and d orbitals and the transformations from the lattice electrons to valence electrons for Cu and In ions. The research results reveal that the photovoltaic effect induces the increase of lattice electrons of In and causes the electric resistivity to decrease. The Eu doping into CuInTe2 mainly influences the transition between different hybridization energy levels for Cu atoms, which shows that the 3d electron numbers of Cu atoms change before and after Eu doping. In single phase CuIn1-xEuxTe2, the number of valence electrons changes regularly with increasing Eu content, and the calculated band gap Eg also increases, which implies that the optical properties of Eu-doped CuIn1-xEuxTe2 are improved.

关键词: CuIn1-xEuxTe2, EET, solar cells, valence electronic structures, band gap

Abstract: The Eu-doped Cu(In, Eu)Te2 semiconductors with chalcopyrite structures are promising materials for their applications in the absorption layer for thin-film solar cells due to their wider band-gaps and better optical properties than those of CuInTe2. In this paper, the Eu-doped CuInTe2 (CuIn1-xEuxTe2, x=0, 0.1, 0.2, 0.3) are studied systemically based on the empirical electron theory (EET). The studies cover crystal structures, bonding regularities, cohesive energies, energy levels, and valence electron structures. The theoretical values fit the experimental results very well. The physical mechanism of a broadened band-gap induced by Eu doping into CuInTe2 is the transitions between different hybridization energy levels induced by electron hopping between s and d orbitals and the transformations from the lattice electrons to valence electrons for Cu and In ions. The research results reveal that the photovoltaic effect induces the increase of lattice electrons of In and causes the electric resistivity to decrease. The Eu doping into CuInTe2 mainly influences the transition between different hybridization energy levels for Cu atoms, which shows that the 3d electron numbers of Cu atoms change before and after Eu doping. In single phase CuIn1-xEuxTe2, the number of valence electrons changes regularly with increasing Eu content, and the calculated band gap Eg also increases, which implies that the optical properties of Eu-doped CuIn1-xEuxTe2 are improved.

Key words: CuIn1-xEuxTe2, EET, solar cells, valence electronic structures, band gap

中图分类号:  (Semi-empirical and empirical calculations (differential overlap, Hückel, PPP methods, etc.))

  • 31.15.bu
88.40.jn (Thin film Cu-based I-III-VI2 solar cells) 88.40.H- (Solar cells (photovoltaics)) 42.70.Nq (Other nonlinear optical materials; photorefractive and semiconductor materials)