Product and Thermoelectric Properties of Thermoelectric Materials with Mesoscopic Structure

在这项研究中，我们可以有两个重要的结果。第一个是观察到热电材料中电子和晶格系统之间的非平衡定态。Peltier效应是典型的热电现象，仅由电子系统体现，晶格系统通过两个系统之间的热相互作用而升温。电子在外加电场的作用下被强制携带。此外，在直流电流的作用下，帕尔蒂埃热不断地被重现。因此，在电子和晶格系统之间可能会出现非平衡定态。我们尝试用在这项研究中开发的设备测量电子和晶格温度，可以确认电子和晶格系统之间的非平衡现象肯定是由Peltier效应引起的。二是提高了铋微线阵列的品质因数。在微线阵列中，优值因子得到了很大的提高，达到ZT=0.287。所得数值约为Bi体器件的2.8倍(ZT=0.1)。此外，我们可以解释说，起源来自于对阵列中晶轴的控制，检查了其他热电物理量的测量值。在这项资助中，我们用Harman方法开发了评估装置，并得到了一些重要的结果，如电子和晶格系统之间的非平衡定态，以及Bi微线阵列品质因数的改善。

We can have two important results in this research. The first is the observation of non-equilibrium stationary state between the electron and lattice systems in thermoelectric materials. Typical thermoelectric phenomenon, The Peltier effect is incarnated by only the electron system and the lattice system is warmed up through the thermal interaction between both systems. The electrons are coercively carried by the applied electric field. Furthermore, the Peltier heat is continuously reproduced during the impression of dc current. Therefore, non-equilibrium stationary state could appear between the electron and lattice systems. We tried to measure the electron and lattice temperatures, using the developed equipment in this grant and could confirm that the non-equilibrium phenomenon between the electron and lattice systems was surely caused by the Peltier effect. The second is improvement of the figure of merit in the Bi micro-wire array. The figure of merit is strongly enhanced to be ZT=0.287 in the micro-wire array. The obtained value is approximately 2.8 times larger than that (ZT=0.1) in the Bi bulk device. Furthermore, we could explain that the origin came from the control of the crystal axis in the array, examining the measured values of the other thermoelectric physical quantities. In this grant we developed the evaluation equipment by the Harman method and some important results such as the non-equilibrium stationary state between the electron and lattice systems and the improvement of the figure of merit in the Bi micro-wire array.