[14p-B12-1~18] 22.1 Joint Session M "Phonon Engineering"

[14p-B12-14] Design of SiGe Alloy and Layered Structure of Low Thermal Conductivity: Phonon Mode analyses

〇Norihiko Takahashi¹, Chioko Kaneta¹ (1.Fujitsu Laboratories Ltd.)

Keywords:SiGe nanostructure, Thermal conductivity, Phonon mode analysis

SiGe systems are expected to be ecofriendly thermoelectric materials and their nanostructures with low thermal conductivity have been designed to achieve high thermoelectric performance. In this study, phonon mode analyses were performed focusing on SiGe alloys and Si/Ge layered structures, both of which are expected to have low thermal conductivity. Participation ratios of SiGe alloys and Si/Ge layered structures, which indicate the spatial localization of each vibrational mode, are reduced in almost all frequency ranges compared with Si and Ge crystals. This result show that most of the vibrational modes of SiGe alloys and Si/Ge layered structures are more localized than Si and Ge crystals, leading to reduction in thermal conductivity.