Direct Observation of Group-V Dopant Substitutional Defects in CdTe Single Crystals

Akira Nagaoka; Koji Kimura; Artoni Kelvin R Ang; Yasuhiro Takabayashi; Kenji Yoshino; Qingde Sun; Baoying Dou; Su-Huai Wei; Koichi Hayashi; Kensuke Nishioka

doi:10.1021/jacs.3c01248

Direct Observation of Group-V Dopant Substitutional Defects in CdTe Single Crystals

J Am Chem Soc. 2023 Apr 26;145(16):9191-9197. doi: 10.1021/jacs.3c01248. Epub 2023 Apr 17.

Authors

Akira Nagaoka^{1

2}, Koji Kimura³, Artoni Kelvin R Ang³, Yasuhiro Takabayashi³, Kenji Yoshino², Qingde Sun^{4

5}, Baoying Dou⁴, Su-Huai Wei⁴, Koichi Hayashi^{3

6}, Kensuke Nishioka^{1

2}

Affiliations

¹ Research Center for Sustainable Energy & Environmental Engineering, University of Miyazaki, Miyazaki 889-2192, Japan.
² Electrical and Electronic Engineering Program, University of Miyazaki, Miyazaki 889-2192, Japan.
³ Department of Physical Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555, Japan.
⁴ Beijing Computational Science Research Center, Beijing 100193, China.
⁵ Hunan Provincial Key Laboratory of Flexible Electronic Materials Genome Engineering, School of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410114, China.
⁶ Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.

PMID: 37125455
DOI: 10.1021/jacs.3c01248

Abstract

Point defect chemistry strongly affects the fundamental properties of materials and has a decisive impact on device performance. The Group-V dopant is prominent acceptor species with high hole concentration in CdTe; however, its local atomic structure is still not clear owing to difficulties in definitive measurements and discrepancies between experimental observations and theoretical models. Herein, we report on direct observation of the local structure for the As dopant in CdTe single crystals by the X-ray fluorescence holography (XFH) technique, which is a powerful tool to visualize three-dimensional atomic configurations around a specific element. The XFH result shows the As substituting on both Cd (As_Cd) and Te (As_Te) sites. Although As_Te has been well known as a shallow acceptor, As_Cd has not attracted much attention and been discussed so far. Our results provide new insights into point defects by expanding the experimental XFH study in combination with theoretical first-principles studies in II-VI semiconductors.