Control of non-equilibrium defects and n-type thin film of environmentally friendly next-generation solar cell material SnS

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02430
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: University of Yamanashi
• Principal Investigator: Yanagi Hiroshi 山梨大学, 大学院総合研究部, 教授 (30361794)
• Co-Investigator(Kenkyū-buntansha): 鈴木 一誓 東北大学, 多元物質科学研究所, 助教 (60821717) ; 川西 咲子 東北大学, 多元物質科学研究所, 助教 (80726985)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: SnS / 太陽電池 / 昇華法

Outline of Final Research Achievements

To increase the Cl concentration in the films, we fabricated thin films using Cl-doped powders and single crystals as source materials and achieved a maximum Cl concentration of 1.8 at.%. By optimizing the film preparation method and conditions to reduce the in-gap states, a highly oriented film with an absorption coefficient of <2x10E4 cm-1 in the bandgap region was successfully fabricated. The carrier concentration was estimated to be <10E16 cm-3. It was also found that the p/n conduction type can be controlled by a slight change in the Sn/S ratio by optimizing the growth conditions of undoped single crystals. Furthermore, p-type SnS was deposited on n-type single crystals by the sublimation method to fabricate pn homojunctions, and clear rectifying properties were observed.

Free Research Field

無機材料科学

Academic Significance and Societal Importance of the Research Achievements

簡便な昇華法などの製膜手法で欠陥濃度の低い薄膜を実現したことやundoped単結晶での不純物添加に頼らず伝導型の制御を実現したことはSnS太陽電池の高効率化に寄与していくものと考えられる。SnSは環境親和性が高く資源制約も少ない材料であるた。今回の研究成果は近い将来低コスト高効率太陽電池を実現しうる薄膜材料として期待させるものである。