论文标题
耗散超晶格结构中优点增强的热电图
Thermoelectric figure of merit enhancement in dissipative superlattice structures
论文作者
论文摘要
利用非连通量子运输形式主义，我们研究了在线性操作方向上跨耗散超晶格配置的热电性能。使用{\ it {dignipative}}非平衡绿色的函数形式主义与泊松方程式耦合在一起，我们报告了多级式设备设计中功绩$ ZT $的增强图。我们表明，提出的增强是通过非连锁运输触发的电子热电导量的急剧降低的结果。我们表明，可以通过包含非连锁弹性散射过程来实现最大$ ZT $值18。 Seebeck系数也有合理的增强，最高为$ 1000〜μv/k $，我们将其归因于非连锁运输引起的电子滤波的增强。显然，随着超晶格的长度缩放，热传导大大降低，尽管功率因子显示总体降解。虽然已知界面的存在会杀死声子热传导，但我们的分析表明，超晶格结构中的非连锁过程也可以有效地杀死电子热传导。我们认为，这里提供的分析可以奠定阶段，以更好地了解异质结构热电设备电子工程中非连锁散射与相干量子过程之间的相互作用。
Utilizing the non-coherent quantum transport formalism, we investigate thermoelectric performance across dissipative superlattice configurations in the linear regime of operation. Using the {\it{dissipative}} non-equilibrium Green's function formalism coupled self-consistently with the Poisson's equation, we report an enhanced figure of merit $zT$ in the multi-barrier device designs. The proposed enhancement, we show, is a result of a drastic reduction in the electronic thermal conductance triggered via non-coherent transport. We show that a maximum $zT$ value of 18 can be achieved via the inclusion of non-coherent elastic scattering processes. There is also a reasonable enhancement in the Seebeck coefficient, with a maximum of $1000~μV/K$, which we attribute to an enhancement in electronic filtering arising from the non-coherent transport. Distinctly the thermal conduction is drastically reduced as the length of the superlattice scales up, although the power factor shows an overall degradation. While the presence of interfaces is known to kill phonon thermal conduction, our analysis shows that non-coherent processes in superlattice structures can effectively kill electronic thermal conduction also. We believe that the analysis presented here could set the stage to understand better the interplay between non-coherent scattering and coherent quantum processes in the electronic engineering of heterostructure thermoelectric devices.
