Processing of semiconductor thin films besed on chemical potential diagram - SnS as a model

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03436
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Metal making/Resorce production engineering
• Research Institution: Kyoto University
• Principal Investigator: Nose Yoshitaro 京都大学, 工学研究科, 准教授 (00375106)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 化学ポテンシャル / 反応拡散 / 蒸留 / ヘテロ界面 / 単結晶 / 二次元材料 / カルコゲナイド

Outline of Final Research Achievements

In this study, we investigated a processing of semiconductor thin films under intentionally-controlling chemical potentials of components, for tin monosulfide (SnS) as a model material. When Sn/MoS3 stacked films were annealed, SnS could be obtained through diffusion of sulfur from MoS3 side to Sn side. However, SnS formed by reactive diffusion evaporated.On the other hand, specimens containing ZnS/SnS interface were obtained by heat treatment of Zn/SnS2 stacked films. The results were expected from chemical potential diagrams, indicating that the prosessing proposed in this study is useful.
In addition, a new method to prepare bulk single crystals and thin films was established by distillation of mixture of Sn and SnS, which was conceived during this study from the fact of high vapor pressure for SnS.

Free Research Field

結晶成長

Academic Significance and Societal Importance of the Research Achievements

本研究では，太陽電池や高速トランジスタなどへの応用が期待される硫化すず(SnS)の新しい作製方法を確立した。硫黄と錫の化合物にはいくつかの種類があり，これを作り分けることは従来困難であったが，本研究では化学ポテンシャル図を地図として作製条件を絞り込むことができた。これはほかの材料系にも適用可能な方法である。
一方で，本研究遂行中に蒸留を利用した簡便な作製方法も着想した。この方法で作製したSnSは高純度であり，薄膜だけでなくバルク単結晶の作製も可能であることを明らかにした。国内外の特許も出願済みである。