Thermoelectric Performance Enhancement of Vanadium Doped n-Type In2O3 Ceramics via Carrier Engineering and Phonon Suppression
Thermoelectric Performance Enhancement of Vanadium Doped n-Type In2O3 Ceramics via Carrier Engineering and Phonon Suppression
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DOI：
10.1021/acsaem.9b02011
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发表时间：
2020-02-01
影响因子：
6.4
通讯作者：
Nan, Ce-Wen
中科院分区：
文献类型：
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作者：
Ahmad, Abid;Hussain, Majid;Nan, Ce-Wen
n型氧化物热电材料由于其平均导电性、高导热性和低热电性能，在各种应用中仍然具有挑战性。在这项工作中，我们研究了通过火花等离子烧结（SPS）制备的掺钒In2O3热电材料的化学、结构和输运性质。V在In2O3中的溶解度约为6% at %，而V4O9作为次级相的溶解度为8% at %。V掺杂导致电导率的协同改善，同时降低了导热系数，在in1.88 v0.120 o3中，在973 K时产生ZT = 0.42，比原始In2O3提高了320%。这种电导率的增强是由于在三价铟位点掺杂五价钒而改变了电荷浓度。由于V掺杂引起的质量波动和取代缺陷的影响，载热声子的散射导致热传导降低。我们的研究结果表明，通过V掺杂可以同时提高PF和降低导热系数，从而改善In2O3的TE性能。
n-Type oxide thermoelectric materials remain challenging for various applications because of their average electrical conductivity, high thermal conductivity, and hence low thermoelectric performance. In this work, we have studied the chemical, structural, and transport properties of vanadium doped In2O3 thermoelectric materials prepared via spark plasma sintering (SPS). The solubility of V in In2O3 is about 6 at % and V4O9 as a secondary phase was observed in 8 at %. V doping leads to a synergistic improvement in electrical conductivity with a simultaneous reduction of the thermal conductivity, yielding ZT = 0.42 at 973 K in In1.88V0.12O3 that is 320% improvement than that of pristine In2O3. This enhancement in electrical conductivity is because of change in charge concentration via pentavalent vanadium doping at the trivalent indium site. The scattering of heat-carrying phonons due to the effects of mass fluctuations and substitutional defects caused by V doping leads to a reduction in heat conduction. Our results suggest that the TE properties of In2O3 can be improved by simultaneously increasing PF and reducing thermal conductivity via V doping.