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arXiv · 2304.06954

Electrical transport properties driven by unique bonding configuration in gamma-GeSe

Jeongsu Jang·Joonho Kim·Dongchul Sung·Jong Hyuk Kim·Joong-Eon Jung·Sol Lee·Jinsub Park·Chaewoon Lee·Heesun Bae·Seongil Im·Kibog Park·Young Jai Choi·Suklyun Hong·Kwanpyo Kim
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Abstract

Group-IV monochalcogenides have recently shown great potential for their thermoelectric, ferroelectric, and other intriguing properties. The electrical properties of group-IV monochalcogenides exhibit a strong dependence on the chalcogen type. For example, GeTe exhibits high doping concentration, whereas S/Se-based chalcogenides are semiconductors with sizable bandgaps. Here, we investigate the electrical and thermoelectric properties of gamma-GeSe, a recently identified polymorph of GeSe. gamma-GeSe exhibits high electrical conductivity (~106 S/m) and a relatively low Seebeck coefficient (9.4 uV/K at room temperature) owing to its high p-doping level (5x1021 cm-3), which is in stark contrast to other known GeSe polymorphs. Elemental analysis and first-principles calculations confirm that the abundant formation of Ge vacancies leads to the high p-doping concentration. The magnetoresistance measurements also reveal weak-antilocalization because of spin-orbit coupling in the crystal. Our results demonstrate that gamma-GeSe is a unique polymorph in which the modified local bonding configuration leads to substantially different physical properties.

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Jeongsu Jang, Joonho Kim, Dongchul Sung, Jong Hyuk Kim, Joong-Eon Jung, Sol Lee, Jinsub Park, Chaewoon Lee, Heesun Bae, Seongil Im, Kibog Park, Young Jai Choi, Suklyun Hong, Kwanpyo Kim. 2023-04-14. Electrical transport properties driven by unique bonding configuration in gamma-GeSe. https://doi.org/10.1021/acs.nanolett.2c04425

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