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arXiv 1908.04547cond-mat.mes-hall
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优化热电generator性能的超晶格设计

Superlattice design for optimal thermoelectric generator performance

Pankaj Priyadarshi, Abhishek Sharma, Swarnadip Mukherjee, Bhaskaran Muralidharan

摘要:

我们考虑通过能量带通滤波器的方法设计一个最佳的超晶格热电发电机。超晶格结构的各种配置进行了探索,以获得带通传输频谱,接近理想的“boxcar”的形式,这是现在众所周知的,以体现在给定的输出功率的最大效率。使用非平衡格林函数形式主义耦合自洽的泊松方程,我们确定这样一个理想的结构,也表明它几乎是免疫的自洽充电和设备的可变性的有害影响。分析各种超晶格设计,我们得出结论,具有高斯分布的势垒厚度的超晶格提供了最佳的热电效率在最大功率。观察到该器件设计的最佳工作状态在卡诺效率的54%-43%之间时提供了0.32-0.46 $MW/m^2$范围内的最大功率。我们还分析了我们的器件设计与传统的品质因数的方法来反支持这样得到的结果。我们注意到一个高的$zT_{el}=6$值的情况下,高斯分布的势垒厚度。利用现有的先进薄膜生长技术,可以实现所建议的超晶格结构,并且可以实现这种优化的热电性能。

英文摘要:

We consider the design of an optimal superlattice thermoelectric generator via the energy bandpass filter approach. Various configurations of superlattice structures are explored to obtain a bandpass transmission spectrum that approaches the ideal ``boxcar'' form, which is now well known to manifest the largest efficiency at a given output power. Using the non-equilibrium Green's function formalism coupled self-consistently with the Poisson's equation, we identify such an ideal structure and also demonstrate that it is almost immune to the deleterious effect of self-consistent charging and device variability. Analyzing various superlattice designs, we conclude that superlattices with a Gaussian distribution of the barrier thickness offers the best thermoelectric efficiency at maximum power. It is observed that the best operating regime of this device design provides a maximum power in the range of 0.32-0.46 $MW/m^2$ at efficiencies between 54\%-43\% of Carnot efficiency. We also analyze our device designs with the conventional figure of merit approach to counter support the results so obtained. We note a high $zT_{el}=6$ value in the case of Gaussian distribution of the barrier thickness. With the existing advanced thin-film growth technology, the suggested superlattice structures can be achieved, and such optimized thermoelectric performances can be realized.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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