Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>
Polycrystalline bulks of Hf-doped Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> are prepared via a conventional melt-solidification process and subsequent spark plasma sintering technology, and their thermoelectric performances are ev...
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MDPI AG
2020-07-01
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| Online Access: | https://www.mdpi.com/2076-3417/10/14/4875 |
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| author | Jeong Yun Hwang Sura Choi Sang-il Kim Jae-Hong Lim Soon-Mok Choi Heesun Yang Hyun-Sik Kim Kyu Hyoung Lee |
| author_facet | Jeong Yun Hwang Sura Choi Sang-il Kim Jae-Hong Lim Soon-Mok Choi Heesun Yang Hyun-Sik Kim Kyu Hyoung Lee |
| author_sort | Jeong Yun Hwang |
| collection | DOAJ |
| description | Polycrystalline bulks of Hf-doped Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> are prepared via a conventional melt-solidification process and subsequent spark plasma sintering technology, and their thermoelectric performances are evaluated. To elucidate the effect of Hf-doping on the thermoelectric properties of <i>n</i>-type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>, electronic and thermal transport parameters are estimated from the measured data. An enlarged density-of-states effective mass (from ~0.92 <i>m</i><sub>0</sub> to ~1.24 <i>m</i><sub>0</sub>) is obtained due to the band modification, and the power factor is improved by Hf-doping benefitting from the increase in carrier concentration while retaining carrier mobility. Additionally, lattice thermal conductivity is reduced due to the intensified point defect phonon scattering that originated from the mass difference between Bi and Hf. Resultantly, a peak thermoelectric figure of merit <i>zT</i> of 0.83 is obtained at 320 K for Cu<sub>0.01</sub>Bi<sub>1.925</sub>Hf<sub>0.075</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>, which is a ~12% enhancement compared to that of the pristine Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>. |
| first_indexed | 2024-03-10T18:27:02Z |
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| language | English |
| last_indexed | 2024-03-10T18:27:02Z |
| publishDate | 2020-07-01 |
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| series | Applied Sciences |
| spelling | doaj.art-c271847274f141858c48785bb5c0916b2023-11-20T06:56:23ZengMDPI AGApplied Sciences2076-34172020-07-011014487510.3390/app10144875Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>Jeong Yun Hwang0Sura Choi1Sang-il Kim2Jae-Hong Lim3Soon-Mok Choi4Heesun Yang5Hyun-Sik Kim6Kyu Hyoung Lee7Department of Materials Science and Engineering, Yonsei University, Seoul 03722, KoreaDepartment of Materials Science and Engineering, Yonsei University, Seoul 03722, KoreaDepartment of Materials Science and Engineering, University of Seoul, Seoul 02504, KoreaDepartment of Materials Science and Engineering, Gachon University, Seongnam 13120, KoreaMaterials and Chemical Engineering, School of Energy, Korea University of Technology and Education, Cheonan 31253, KoreaDepartment of Materials Science and Engineering, Hongik University, Seoul 04066, KoreaDepartment of Materials Science and Engineering, Hongik University, Seoul 04066, KoreaDepartment of Materials Science and Engineering, Yonsei University, Seoul 03722, KoreaPolycrystalline bulks of Hf-doped Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> are prepared via a conventional melt-solidification process and subsequent spark plasma sintering technology, and their thermoelectric performances are evaluated. To elucidate the effect of Hf-doping on the thermoelectric properties of <i>n</i>-type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>, electronic and thermal transport parameters are estimated from the measured data. An enlarged density-of-states effective mass (from ~0.92 <i>m</i><sub>0</sub> to ~1.24 <i>m</i><sub>0</sub>) is obtained due to the band modification, and the power factor is improved by Hf-doping benefitting from the increase in carrier concentration while retaining carrier mobility. Additionally, lattice thermal conductivity is reduced due to the intensified point defect phonon scattering that originated from the mass difference between Bi and Hf. Resultantly, a peak thermoelectric figure of merit <i>zT</i> of 0.83 is obtained at 320 K for Cu<sub>0.01</sub>Bi<sub>1.925</sub>Hf<sub>0.075</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>, which is a ~12% enhancement compared to that of the pristine Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub>.https://www.mdpi.com/2076-3417/10/14/4875Bi<sub>2</sub>Te<sub>3</sub>thermoelectricHf-dopingeffective masslattice thermal conductivity |
| spellingShingle | Jeong Yun Hwang Sura Choi Sang-il Kim Jae-Hong Lim Soon-Mok Choi Heesun Yang Hyun-Sik Kim Kyu Hyoung Lee Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> Applied Sciences Bi<sub>2</sub>Te<sub>3</sub> thermoelectric Hf-doping effective mass lattice thermal conductivity |
| title | Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> |
| title_full | Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> |
| title_fullStr | Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> |
| title_full_unstemmed | Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> |
| title_short | Hf-Doping Effect on the Thermoelectric Transport Properties of <i>n</i>-Type Cu<sub>0.01</sub>Bi<sub>2</sub>Te<sub>2.7</sub>Se<sub>0.3</sub> |
| title_sort | hf doping effect on the thermoelectric transport properties of i n i type cu sub 0 01 sub bi sub 2 sub te sub 2 7 sub se sub 0 3 sub |
| topic | Bi<sub>2</sub>Te<sub>3</sub> thermoelectric Hf-doping effective mass lattice thermal conductivity |
| url | https://www.mdpi.com/2076-3417/10/14/4875 |
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