Study on evaluation of thermal properties for thermoelectric Si device by temperature dependent X-ray diffraction with synchrotron radiation

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K22418
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0302:Electrical and electronic engineering and related fields
• Research Institution: Meiji University
• Principal Investigator: Yokogawa Ryo 明治大学, 理工学部, 助教 (10880619)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: シリコン / 熱電変換 / 酸化膜 / 界面 / X線回折 / 放射光

Outline of Final Research Achievements

In order to realize a high-efficiency thermoelectric device, we demonstrated evaluation of thermal properties in silicon (Si) using temperature dependent X-ray diffraction with synchrotron radiation. In order to further dramatically reduce the thermal conductivity of Si, it is important to induce phonon scattering. In this study, we focused on covering oxide film on Si to achieve low thermal conductivity of Si. Oxide films were covered with Si by different processes, and the X-ray scattering intensity profiles obtained by X-ray diffraction with synchrotron radiation were compared and examined to evaluate an effect on heat transport near the Si interface.

Free Research Field

結晶工学

Academic Significance and Societal Importance of the Research Achievements

本研究で用いた放射光X線回折で得られるCrystal truncation rod (CTR)散乱は酸化膜/Si界面の構造に敏感であり、Si微小領域の熱伝導特性に有効であることが示唆された。また、Si酸化膜被覆プロセスによってX線散乱強度分布が異なったことから、高効率熱電発電デバイスへ向けてSi酸化膜被覆プロセスを適切に選択する必要があることを示した。そして放射光X線回折は熱電発電デバイスプロセスの1つの評価手法として有効であり、今後も応用が期待される。