Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ
The InTe has intrinsically low lattice thermal conductivity κL originating from the anharmonic bonding of In1+ ion in the lattice, which scatters the phonons. Here we report the enhancement of thermoelectric properties in Te-deficient InTe1−δ (δ = 0, 0.01, 0.1, and 0.2) polycrystalline compounds by...
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2018-11-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/1.5063274 |
| _version_ | 1828169414593216512 |
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| author | Song Yi Back Hyunyong Cho Young-Kwang Kim Seokyeong Byeon Hyungyu Jin Kunihito Koumoto Jong-Soo Rhyee |
| author_facet | Song Yi Back Hyunyong Cho Young-Kwang Kim Seokyeong Byeon Hyungyu Jin Kunihito Koumoto Jong-Soo Rhyee |
| author_sort | Song Yi Back |
| collection | DOAJ |
| description | The InTe has intrinsically low lattice thermal conductivity κL originating from the anharmonic bonding of In1+ ion in the lattice, which scatters the phonons. Here we report the enhancement of thermoelectric properties in Te-deficient InTe1−δ (δ = 0, 0.01, 0.1, and 0.2) polycrystalline compounds by lattice softening and energy band gap opening. Te-deficiency gives rise to more weak chemical bonding between In1+ atoms and In3+Te2− clusters than those of pristine InTe, resulting in the reduction of κL near the room temperature. The weak ionic bonding is confirmed by the increase of lattice volume from the X-ray diffraction and lattice softening by the decrease of Debye temperature with increasing Te-deficiency. We observed the low lattice thermal conductivity κL of 0.53 W m−1 K−1 at 300 K for InTe0.99, which is about 25 % decreased value than those of InTe. The Te-deficiency also induces energy band gap so that the electrical resistivity and Seebeck coefficient are increased due to the decrease of carrier concentration. Temperature-dependent thermoelectric properties shows the high Seebeck coefficient at high temperature and high electrical conductivity near room temperature, resulting in the temperature-insensitive high power factor S2σ over a wide temperature range. Owing to the temperature-insensitive high power factor and intrinsic low lattice thermal conductivity by Te-deficiency, the thermoelectric performances of figure-of-merit ZT and engineering ZTeng are enhanced at mild temperature range (≤550 K). |
| first_indexed | 2024-04-12T02:51:10Z |
| format | Article |
| id | doaj.art-bf06092fcbb842c18d0c8b0961bfa585 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-12T02:51:10Z |
| publishDate | 2018-11-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-bf06092fcbb842c18d0c8b0961bfa5852022-12-22T03:50:59ZengAIP Publishing LLCAIP Advances2158-32262018-11-01811115227115227-1110.1063/1.5063274109811ADVEnhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δSong Yi Back0Hyunyong Cho1Young-Kwang Kim2Seokyeong Byeon3Hyungyu Jin4Kunihito Koumoto5Jong-Soo Rhyee6Department of Applied Physics and Institute of Basic Sciences, Kyung Hee University, Yongin 17104, KoreaDepartment of Applied Physics and Institute of Basic Sciences, Kyung Hee University, Yongin 17104, KoreaDepartment of Materials Science and Engineering, Pohang University of Science and Technology, Pohang 37673, South KoreaDepartment of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, South KoreaDepartment of Mechanical Engineering, Pohang University of Science and Technology, Pohang 37673, South KoreaDepartment of Applied Physics and Institute of Basic Sciences, Kyung Hee University, Yongin 17104, KoreaDepartment of Applied Physics and Institute of Basic Sciences, Kyung Hee University, Yongin 17104, KoreaThe InTe has intrinsically low lattice thermal conductivity κL originating from the anharmonic bonding of In1+ ion in the lattice, which scatters the phonons. Here we report the enhancement of thermoelectric properties in Te-deficient InTe1−δ (δ = 0, 0.01, 0.1, and 0.2) polycrystalline compounds by lattice softening and energy band gap opening. Te-deficiency gives rise to more weak chemical bonding between In1+ atoms and In3+Te2− clusters than those of pristine InTe, resulting in the reduction of κL near the room temperature. The weak ionic bonding is confirmed by the increase of lattice volume from the X-ray diffraction and lattice softening by the decrease of Debye temperature with increasing Te-deficiency. We observed the low lattice thermal conductivity κL of 0.53 W m−1 K−1 at 300 K for InTe0.99, which is about 25 % decreased value than those of InTe. The Te-deficiency also induces energy band gap so that the electrical resistivity and Seebeck coefficient are increased due to the decrease of carrier concentration. Temperature-dependent thermoelectric properties shows the high Seebeck coefficient at high temperature and high electrical conductivity near room temperature, resulting in the temperature-insensitive high power factor S2σ over a wide temperature range. Owing to the temperature-insensitive high power factor and intrinsic low lattice thermal conductivity by Te-deficiency, the thermoelectric performances of figure-of-merit ZT and engineering ZTeng are enhanced at mild temperature range (≤550 K).http://dx.doi.org/10.1063/1.5063274 |
| spellingShingle | Song Yi Back Hyunyong Cho Young-Kwang Kim Seokyeong Byeon Hyungyu Jin Kunihito Koumoto Jong-Soo Rhyee Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ AIP Advances |
| title | Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ |
| title_full | Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ |
| title_fullStr | Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ |
| title_full_unstemmed | Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ |
| title_short | Enhancement of thermoelectric properties by lattice softening and energy band gap control in Te-deficient InTe1−δ |
| title_sort | enhancement of thermoelectric properties by lattice softening and energy band gap control in te deficient inte1 δ |
| url | http://dx.doi.org/10.1063/1.5063274 |
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