Boosting Thermoelectric Performance in Epitaxial GeTe Film/Si by Domain Engineering and Point Defect Control

• DOI: 10.1021/acsami.3c01404
• Publication Date: 2023-05-16T15:02:17Z
• Authors: Takafumi Ishibe; Yuki Komatsubara; Kodai Ishikawa; Sho Takigawa; Nobuyasu Naruse; Yutaka Mera; Yuichiro Yamashita; Yuji Ohishi; Yoshiaki Nakamura
• Keywords: Misorientation

This study demonstrates a simultaneous realization of ultralow thermal conductivity and high thermoelectric power factor in epitaxial GeTe thin films/Si substrates by combination the interface introduction domain engineering suppression Ge vacancy generation point defect control. We formed Te-poor films having low-angle grain boundaries with misorientation angle close to 0° or twin interfaces 180°. The control defects gave rise lattice ∼0.7 ± 0.2 W m-1 K-1. value was same order magnitude as theoretical minimum ∼0.5 K-1 calculated Cahill-Pohl model. At time, exhibited because small contribution boundary carrier scattering. outstanding combined technique can be great approach for developing high-performance films.