Elucidation of effects of interfacial electronic states on thermoelectric properties of core-shell Si nanowires

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K15150
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 28050:Nano/micro-systems-related
• Research Institution: Kobe University
• Principal Investigator: Uesugi Akio 神戸大学, 工学研究科, 助教 (90821710)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: シリコンナノワイヤ / 熱電発電 / コア/シェル半導体 / ナノ構造 / 集積化技術

Outline of Final Research Achievements

In order to clarify the effect of the interfacial surface potential induced by core-shell structuring with dielectric films on the thermoelectric properties of silicon nanowires, a new method for integration of crystal-grown silicon nanowire bridges and evaluation device corresponding to the method were developed, and evaluations of the thermoelectric properties of core-shell silicon nanowires were performed. Evaluation results indicated a potential of improving thermoelectric efficiency on p-type silicon nanowires by core-shell structuring with Al2O3 film, because of relationship change between Seebeck coefficient and electrical conductivity.

Free Research Field

ナノマイクロ科学

Academic Significance and Societal Importance of the Research Achievements

本研究の中で提案した結晶成長SiNWsの成長方位制御手法と架橋集積手法は良好な結果を示し、これは熱電特性評価構造や発電モジュールの構築だけでなく、ナノワイヤを用いた様々な微小センサや電子素子の構築へと貢献しうるものである。またこれまでに報告されているp型シリコンナノ構造のゼーベック係数は、同キャリア濃度ではバルクの傾向よりも大きく下回る低い傾向にあったが、コアシェル構造化はナノ構造の傾向を変化させる可能性を持つことが示され、これはナノ構造を用いた熱電発電モジュールの性能向上に貢献しうるものである。