title: Superionic adjustment leading to weakly temperature-dependent ZT values in bulk thermoelectrics.
abstract: Thermoelectric (TE) materials are of worldwide interest for energy sustainability through direct waste-heat-to-electricity conversion. Practically, a TE power generator requires a large working temperature gradient; to achieve high efficiency, key TE materials with high ZT values are necessary and, furthermore, their ZT values should decline as little as possible over the imposed temperature range. Unfortunately, sharp ZT declines in all of the known materials are inevitable. Here we found the bulk superionic α-Ag(1-x)CuSe material exhibits unusual weakly temperature-dependent ZT values in the range of 480-693 K with the smallest ZT-T slope known to date. These result from the Seebeck coefficient balance of the countercontributions of holes and electrons and the weakly temperature-dependent thermal conductivity.
authors.affiliation: State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences , Fuzhou, Fujian 350002, People's Republic of China.
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Hua
authors.initials: H
authors.lastname: Lin
authors.forename: Zi-Xiong
authors.initials: ZX
authors.lastname: Lin
authors.forename: Jin-Ni
authors.initials: JN
authors.lastname: Shen
authors.forename: Ling
authors.initials: L
authors.lastname: Chen
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Wu