Distinctive Deep-Level Defects in Non-Stoichiometric Sb2 Se3 Photovoltaic Materials

Weitao Lian; Rui Cao; Gang Li; Huiling Cai; Zhiyuan Cai; Rongfeng Tang; Changfei Zhu; Shangfeng Yang; Tao Chen

doi:10.1002/advs.202105268

Distinctive Deep-Level Defects in Non-Stoichiometric Sb₂ Se₃ Photovoltaic Materials

Adv Sci (Weinh). 2022 Mar;9(9):e2105268. doi: 10.1002/advs.202105268. Epub 2022 Jan 25.

Authors

Weitao Lian^{1

2}, Rui Cao^{1

2}, Gang Li^{1

2}, Huiling Cai^{1

2}, Zhiyuan Cai^{1

2}, Rongfeng Tang^{1

2}, Changfei Zhu^{1

2}, Shangfeng Yang^{1

2}, Tao Chen^{1

2}

Affiliations

¹ Hefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Materials for Energy Conversion, Department of Materials Science and Engineering, School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, Anhui, 230026, China.
² Institute of Energy, Hefei Comprehensive National Science Center, Hefei, China.

Abstract

Characterizing defect levels and identifying the compositional elements in semiconducting materials are important research subject for understanding the mechanism of photogenerated carrier recombination and reducing energy loss during solar energy conversion. Here it shows that deep-level defect in antimony triselenide (Sb₂ Se₃ ) is sensitively dependent on the stoichiometry. For the first time it experimentally observes the formation of amphoteric Sb_Se defect in Sb-rich Sb₂ Se₃ . This amphoteric defect possesses equivalent capability of trapping electron and hole, which plays critical role in charge recombination and device performance. In comparative investigation, it also uncovers the reason why Se-rich Sb₂ Se₃ is able to deliver high device performance from the defect formation perspective. This study demonstrates the crucial defect types in Sb₂ Se₃ and provides a guidance toward the fabrication of efficient Sb₂ Se₃ photovoltaic device and relevant optoelectronic devices.

Keywords: DLTS; SRH recombination; antimony triselenide; carrier lifetime; deep-level defect.

Abstract

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