Anion-site-modulated thermoelectric properties in Ge2Sb2Te5-based compounds
Anion-site-modulated thermoelectric properties in Ge2Sb2Te5-based compounds
复制标题
Ge2Sb2Te5 基化合物的阴离子位点调节热电性能
DOI：
10.1007/s12598-020-01476-4
复制
发表时间：
2020-07-01
期刊：
影响因子：
8.8
通讯作者：
Shi, Xun
中科院分区：
文献类型：
--
作者：
Hu, Ping;Wei, Tian-Ran;Shi, Xun
The amalgamation of multi-subjects often elicits novel materials, new concepts and unexpected applications. Recently, Ge2Sb2Te5, as the most established phase-change material, has been found to exhibit decent thermoelectric performance in its stable, hexagonal phase. The challenge for higher figure of merit (zT) values lies in reducing the hole carrier concentration and enhancing the Seebeck coefficient, which, however, can be hardly realized by conventional doping. Here in this work, we report that the electrical properties of Ge2Sb2Te5can be readily optimized by anion-site modulation. Specifically, Se/S substitution for Te induces stronger and more ionic bonding, lowering the hole density. Furthermore, an increase in electronic density of state is introduced by Se substitution, contributing to a large increase in Seebeck coefficient. Combined with the reduced thermal conductivity, maximumzTvalues above 0.7 at 800 K have been achieved in Se/S-alloyed materials, which is ~ 30% higher than that in the pristine Ge2Sb2Te5.
