Optimization of Sulfide Annealing Conditions for Ag8SnS6 Thin Films

Ryuki Munekata; Tomohiro Uchimura; Hideaki Araki; Ayaka Kanai; Kunihiko Tanaka; Tomoichiro Okamoto; Yoji Akaki

doi:10.3390/ma16186289

Optimization of Sulfide Annealing Conditions for Ag₈SnS₆ Thin Films

Materials (Basel). 2023 Sep 19;16(18):6289. doi: 10.3390/ma16186289.

Authors

Ryuki Munekata¹, Tomohiro Uchimura², Hideaki Araki³, Ayaka Kanai⁴, Kunihiko Tanaka⁴, Tomoichiro Okamoto⁴, Yoji Akaki¹

Affiliations

¹ National Institute of Technology (KOSEN), Miyakonojo College, Miyakonojo 885-8567, Japan.
² Laboratory for Nanoelectronics and Spintronics, Research Institute of Electrical Communication, Tohoku University, Sendai 980-8576, Japan.
³ National Institute of Technology (KOSEN), Nagaoka College, Nagaoka 940-8532, Japan.
⁴ Department of Electrical, Electronics and Information EngineeringElectronic Device and Light Wave Control Engineering Group, Nagaoka University of Technology, Nagaoka 940-2218, Japan.

Abstract

Ag₈SnS₆ (ATS) has been reported to have a band gap of 1.33 eV and is expected to be a suitable material for the light-absorbing layers of compound thin-film solar cells. However, studies on solar cells that use ATS are currently lacking. The objective of this study is to obtain high-quality ATS thin films for the realization of compound thin-film solar cells using vacuum deposition and sulfide annealing. First, glass/SnS/Ag stacked precursors are prepared by vacuum deposition. Subsequently, they are converted to the ATS phase via sulfide annealing, and various process conditions, namely, annealing time, annealing temperature, and number of steps, are studied. By setting the heat treatment temperature at 550 °C and the heat treatment time at 60 min, a high-quality ATS thin film could be obtained. Multi-step heat treatment also produces thin films with nearly no segregation or voids.

Keywords: Ag8SnS6 thin film; annealing condition; multistage annealing.

Grants and funding

Part of this research was supported by the Nagaoka University of Technology grant for collaborative research from the National Institute of Technology, Japan.