TY - JOUR AU - Juan Li AU - Xinyue Zhang AU - Zhiwei Chen AU - Siqi Lin AU - Wen Li AU - Jiahong Shen AU - Ian T Witting AU - Alireza Faghaninia AU - Yue Chen AU - Anubhav Jain AU - Lidong Chen AU - G. G Jeffrey Snyder AU - Yanzhong Pei AB -

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.

BT - Joule DA - 05/2018 DO - 10.1016/j.joule.2018.02.016 IS - 5 LA - eng N2 -

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.

PY - 2018 SP - 976 EP - 987 ST - Joule T2 - Joule TI - Low-Symmetry Rhombohedral GeTe Thermoelectrics VL - 2 SN - 25424351 ER -