Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 145-153 |
| Number of pages | 9 |
| Journal | Acta Materialia |
| Volume | 144 |
| DOIs | |
| Publication status | Published - 2018 Feb 1 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys
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Strain-engineered allotrope-like bismuth nanowires for enhanced thermoelectric performance. / 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.
In: Acta Materialia, Vol. 144, 01.02.2018, p. 145-153.Research output: Contribution to journal › Article
TY - JOUR
T1 - Strain-engineered allotrope-like bismuth nanowires for enhanced thermoelectric performance
AU - Kim, Jeongmin
AU - Oh, Min Wook
AU - Kim, Gwansik
AU - Bahk, Je Hyeong
AU - Song, Jae Yong
AU - Jeon, Seong Gi
AU - Chun, Dong Won
AU - Bae, Jee Hwan
AU - Shim, Wooyoung
AU - Lee, Wooyoung
PY - 2018/2/1
Y1 - 2018/2/1
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85032795116&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85032795116&partnerID=8YFLogxK
U2 - 10.1016/j.actamat.2017.10.062
DO - 10.1016/j.actamat.2017.10.062
M3 - Article
AN - SCOPUS:85032795116
VL - 144
SP - 145
EP - 153
JO - Acta Materialia
JF - Acta Materialia
SN - 1359-6454
ER -