|Title||Low-Symmetry Rhombohedral GeTe Thermoelectrics|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Juan Li, Xinyue Zhang, Zhiwei Chen, Siqi Lin, Wen Li, Jiahong Shen, Ian T Witting, Alireza Faghaninia, Yue Chen, Anubhav Jain, Lidong Chen, G. Jeffrey Snyder, Yanzhong Pei|
|Pagination||976 - 987|
Thermoelectric materials enable a heat flow to be directly converted to a flow of charge carriers for generating electricity. The crystal structure symmetry is one of the most fundamental parameters determining the properties of a crystalline material including thermoelectrics. The common belief currently held is that high-symmetry materials are usually good for thermoelectrics, leading to great efforts having historically been focused on GeTe alloys in a high-symmetry cubic structure. Here we show a slight reduction of crystal structure symmetry of GeTe alloys from cubic to rhombohedral, enabling a rearrangement in electronic bands for more transporting channels of charge carriers and many imperfections for more blocking centers of heat-energy carriers (phonons). This leads to the discovery of rhombohedral GeTe alloys as the most efficient thermoelectric materials to date, opening new possibilities for low-symmetry thermoelectric materials.