| 학회 |
한국재료학회 |
| 학술대회 |
2021년 봄 (05/12 ~ 05/14, 광주 김대중컨벤션센터) |
| 권호 |
27권 1호 |
| 발표분야 |
A. 전자/반도체 재료 분과 |
| 제목 |
n-type Thermoelectric Properties of a Hexagonal SiGe Polymorph Superior to Cubic SiGe |
| 초록 |
The crystal structure of a material dictates many of its properties. This study focuses on a SiGe compound with a hexagonal crystal system that demonstrates superior thermoelectric properties than those of its conventional cubic polymorph. Using first-principles density functional theory (DFT) calculations combined with the semi-classical Boltzmann transport equation (BTE), we clearly elucidate the underlying mechanisms that cause the enhanced thermoelectric performance. The hexagonal SiGe compound shows very distinct electronic band structures and phonon dispersion relations. Their unique transport behaviors lead to dissimilar electrical properties and thermal conductivities compared with those of its cubic counterpart. Specifically, the configuration of the electron conduction band and local symmetry of the phonon vibrational modes in hexagonal SiGe remarkably increase the Seebeck coefficient and phonon scattering rate, respectively. We propose that hexagonal SiGe is a very promising material for highly active n-type thermoelectric materials with a figure of merit more than twice that of its cubic analogue. Our approach demonstrates an attractive method for substantially enhancing conventional material properties without a complicated or expensive process for developing a novel material. |
| 저자 |
홍성준, 전호제, 권초아, 한병찬
|
| 소속 |
연세대 |
| 키워드 |
SiGe; First-principles study; Boltzmann transport equation; Polymorph; Thermoelectric
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| E-Mail |
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