Kim, Jeongmin Oh, Min-Wook Kim, Gwansik Bahk, Je-Hyeong Song, Jae Yong Jeon, Seong Gi Chun, Dong Won Bae, Jee Hwan Shim, Wooyoung Lee, Wooyoung 2024-01-19T23:31:32Z 2024-01-19T23:31:32Z 2021-09-03 2018-02 1359-6454 https://pubs.kist.re.kr/handle/201004/121720 Allotropy is a fundamental concept that has been frequently studied since the mid-1800s. Although the bulk allotropy of elemental solids is fairly well understood, it remains challenging to reliably produce an allotrope at the nanoscale that has a different crystal structure and accompanies a change in physical properties for specific applications. Here, we demonstrate a "heterostructure" approach to produce allotrope-like bismuth nanowires, where it utilizes the lattice constant difference between bismuth and tellurium in core/shell structure. We find that the resultant strain of [100]-grown Bi nanowires increases the atomic linear density along the c-axis that has been predicted from theoretical considerations, enabling us to establish a design rule for strain-induced allotropic transformation. With our >400-nm-diameter nanowires, we measure a thermoelectric figure of merit ZT of 0.5 at room temperature with reduced thermal conductivity and enhanced Seebeck coefficient, which are primarily a result of the rough interface and the reduced band overlap according to our density-functional calculations. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. English PERGAMON-ELSEVIER SCIENCE LTD Strain-engineered allotrope-like bismuth nanowires for enhanced thermoelectric performance Article 10.1016/j.actamat.2017.10.062 1 ACTA MATERIALIA, v.144, pp.145 - 153 ACTA MATERIALIA 144 145 153 N scie scopus 000424067100015 2-s2.0-85032795116 Materials Science, Multidisciplinary Metallurgy & Metallurgical Engineering Materials Science Metallurgy & Metallurgical Engineering Article INITIO MOLECULAR-DYNAMICS THERMAL-CONDUCTIVITY SEMICONDUCTOR TRANSITION ELECTRICAL-PROPERTIES BI NANOWIRES FIGURE MERIT CRYSTALS FILMS Thermoelectric Figure of merit Strained nanowire Bismuth nanowire Band engineering