Ultrahigh Thermoelectric Performance in SrNb0.2Ti0.8O3 Oxide Films at a Submicrometer-Scale Thickness
Ultrahigh Thermoelectric Performance in SrNb0.2Ti0.8O3 Oxide Films at a Submicrometer-Scale Thickness
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DOI：
10.1021/acsenergylett.7b00197
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发表时间：
2017-03
影响因子：
22
通讯作者：
Jikun Chen;Hongyi Chen;Feng Hao;Xinyou Ke;N. Chen;T. Yajima;Yong Jiang;Xun Shi;K. Zhou;M. Döbeli;Tiansong Zhang;B. Ge;Hongliang Dong;H. Zeng;Wenwang Wu;Lidong Chen
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文献类型：
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作者：
Jikun Chen;Hongyi Chen;Feng Hao;Xinyou Ke;N. Chen;T. Yajima;Yong Jiang;Xun Shi;K. Zhou;M. Döbeli;Tiansong Zhang;B. Ge;Hongliang Dong;H. Zeng;Wenwang Wu;Lidong Chen
通过热电技术实现的局部制冷和发电依赖于在室温下具有高性能的高效热电材料。虽然二维电子气（2DEG）相关材料在室温附近表现出良好的热电性能，但这种性能仅在亚纳米尺度的厚度下保持，受到二维尺寸限制的限制。在这里，我们报告的热电性能类似于2DEG相关的材料，但实现在SrNb0.2Ti0.8O3氧化物薄膜的亚微米级的厚度，通过调节应变诱导的晶格极化和界面极化。在室温附近获得了较大的品质因数、zT和功率因子（102-103 μW cm-1 K-2），对于49 nm厚的薄膜，最大zT估计为1.6。这些性能超过了现有的室温用n型热电材料和报道的最好的氧化物材料超过亚纳米级。
Localized refrigeration and power generation via thermoelectric technology rely on efficient thermoelectric materials with high performance at room temperature. Although the two-dimensional electron gas (2DEG)-related materials exhibit ultrahigh thermoelectric performance near room temperature, such performance is only preserved at thicknesses within subnanometer scales, limited by the requirement of two-dimensional size confinements. Here we report ultrahigh thermoelectric performance similar to 2DEG-related materials but achieved in SrNb0.2Ti0.8O3 oxide films with a submicrometer-scale thickness by regulating strain-induced lattice polarizations and interfacial polarizations. A large figure of merit, zT, and power factor (∼102–103 μW cm–1 K–2) were achieved near room temperature, and the maximum zT is estimated to be ∼1.6 for a 49 nm thick film. These performances exceed those of the existing n-type thermoelectric materials for room-temperature uses and the reported best oxide materials beyond subnanome...