Crystal structure of Cu$_2$Te predicted within adaptive genetic algorithm

ORAL

Abstract

Cu$_2$Te is one of the most commonly used conductive back-contacting materials for high-efficiency CdTe-based solar cells. However, the detailed crystal structure of Cu$_2$Te is still undetermined blocking property investigations of the Cu$_2$Te-based solar cell systems. Some models have been proposed but all of them have positive formation energy [1]. We have performed adaptive genetic algorithm crystal structure search to find low energy crystal structures of Cu$_2$Te. We found a new layered-structure edged by Te atoms with negative formation energy from first-principles calculations within local density approximation. This layered structure consists of tilted Cu$_2$Te ribbon arrays. Structural and electronic properties of the newly found Cu$_2$Te structure will be discussed in detail.\\[4pt] [1] J. L. F. Da Silva, S.-H. Wei, J. Zhou, and X. Wu, Appl. Phys. Lett. 91, 091902 (2007)

*Supported in part US DOE, NSF of China, and US NSF.

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Authors

  • Kai-Ming Ho

    • Iowa State University
    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
    • Ames Laboratory and Iowa State University
    • Ames Laboratory
    • Ames Laboratory-US Department of Energy, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA

  • Manh Cuong Nguyen

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA

  • Jin-Ho Choi

    • ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
    • University of Science and Technology of China

  • Cai-Zhuang Wang

    • Iowa State University
    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
    • Ames Laboratory and Iowa State University
    • Ames Laboratory
    • Ames Laboratory-US Department of Energy, and Department of Physics and Astronomy, Iowa State University, Ames, Iowa, 50011, USA

  • Xin Zhao

    • Ames Laboratory, US DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA

  • Zhenyu Zhang

    • University of Science and Technology of China
    • ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui, 230026, China
    • Univ. of Sci. \& Tech. of China, Harvard University
    • Univ of Science \& Technology of China \& Univ of Texas at Austin
    • ICQD, Hefei National Laboratory for Physical Sciences at Microscales, University of Science and Technology of China
    • ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China