title: Solid-solutioned homojunction nanoplates with disordered lattice: a promising approach toward "phonon glass electron crystal" thermoelectric materials.
abstract: The concept of "phonon glass electron crystal" (PGEC) was proposed in the mid-1990s to maximize the ZT value for thermoelectric materials, based on its combined advantages of low thermal conductivity as in a glass but high electricity as in a well-ordered crystal. Although a great amount of research in complex materials systems for achieving this concept has been done, a perfect "PGEC" material has not been acquired yet. Herein, we first put forward a solid-solutioned homojunction in high temperature phase with disordered lattice, which possesses both high electrical conductivity and low thermal conductivity, as an effective way to optimize the low/mid-temperature thermoelectric property. As an example, nonambient cubic phase AgBiSe(2) was successfully stabilized to room temperature through the formation of a solid solution by Sb incorporation for the first time, and furthermore, in situ formed homojunctions on the surface of solid-solutioned nanoplates were also first achieved through a simple colloidal method. A significant enhancement of thermoelectric performance at low/mid-temperature was realized through synergistical regulation on electronic and thermal transport. As a result, compared to that of original AgBiSe(2) (ZT = 0.03 at 550 K), the ZT value of AgBi(0.5)Sb(0.5)Se(2) was increased to 0.51 at 550 K by the formation of a solid solution, and then further increased to 1.07 at 550 K by the formation of solid-solutioned homojunction.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science & Technology of China, Hefei, Anhui 230026, P.R. China.
authors.forename: Chong
authors.initials: C
authors.lastname: Xiao
authors.forename: Jie
authors.initials: J
authors.lastname: Xu
authors.forename: Boxiao
authors.initials: B
authors.lastname: Cao
authors.forename: Kun
authors.initials: K
authors.lastname: Li
authors.forename: Mingguang
authors.initials: M
authors.lastname: Kong
authors.forename: Yi
authors.initials: Y
authors.lastname: Xie