论文标题
具有逼真散射和带的热电学的最佳带结构
Optimal Band Structure for Thermoelectrics with Realistic Scattering and Bands
论文作者
论文摘要
了解如何优化热电学的电子带结构是社区长期兴趣的话题。先前的模型仅限于简化的频段和/或散射模型。在这项研究中，我们将更严格的散射处理应用于更逼真的模型带结构 - 向上抛物面带，这些抛物性带呈倒置抛物面行为 - 包括多个带的病例。与常见的描述符（例如质量因子和复杂性因子）相反，多个口袋改善热电性能的程度是由带间散射和带的相对形状界定的。我们确定极端各向异性的“扁平与分散”频带虽然在理论上表现最好，但在实践中可能并不代表有前途的设计策略。至关重要的是，我们确定最佳带宽，取决于温度和晶格导热率，从理论上可以显着提高$ zt $的完美传输截止，而不是仅通过固有的带结构就可以实现的值。我们的分析应该广泛用来，因为热电研究社区的眼睛$ ZT> 3 $。
Understanding how to optimize electronic band structures for thermoelectrics is a topic of long-standing interest in the community. Prior models have been limited to simplified bands and/or scattering models. In this study, we apply more rigorous scattering treatments to more realistic model band structures - upward-parabolic bands that inflect to an inverted parabolic behavior - including cases of multiple bands. In contrast to common descriptors (e.g., quality factor and complexity factor), the degree to which multiple pockets improve thermoelectric performance is bounded by interband scattering and the relative shapes of the bands. We establish that extremely anisotropic `flat-and-dispersive' bands, although best-performing in theory, may not represent a promising design strategy in practice. Critically, we determine optimum bandwidth, dependent on temperature and lattice thermal conductivity, from perfect transport cutoffs that can in theory significantly boost $zT$ beyond the values attainable through intrinsic band structures alone. Our analysis should be widely useful as the thermoelectric research community eyes $zT>3$.
