Maximizing thermoelectric properties by nanoinclusion of γ-SbTe in Sb2Te3 film via solid-state phase transition from amorphous Sb–Te electrodeposits. (April 2015)

• Record Type: Journal Article
• Authors: Kim, Jiwon; Zhang, Miluo; Bosze, Wayne; Park, Su-Dong; Lim, Jae-Hong; Myung, Nosang V.
• Is Part Of: Nano energy. Volume 13(2015:Apr.)
• Page Start: 727
• Page End: 734
• Publication Date: 2015-04
• Subjects: Thermoelectrics (TE) -- Antimony telluride (Sb–Te) -- Structural transformation -- Nanocomposites -- Electrodeposition; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2015.03.020
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: In this work, we demonstrate an enhancement of thermoelectric properties by creating γ-SbTe/Sb2 Te3 nanocomposite film, where γ-SbTe nanoinclusions are embedded in a nanocrystalline Sb2 Te3 matrix. The two-phase nanocomposite was formed via solid-state phase transition using an amorphous Sb2 Te3 electrodeposits as the starting materials. The crystallinity and crystal structure of intermediate states during the amorphous-crystalline solid-state transformation were characterized by sequentially annealing the sample. The formation of the γ-SbTe is attributed to the different enthalpy of mixing for the bonding structures available in the Sb–Te system. Room temperature measurement of electrical and thermoelectrical properties as a function of annealing temperature revealed that the two-phase system provided the carrier energy filtering effect at the interfaces between two phases, leading to enhanced Seebeck coefficient without affecting its electrical transport properties. The band bending at the two-phase interfaces was indirectly manifested by measuring their difference in the valence band, advocating the possibility of a strong energy-dependent charge scattering to the enhanced Seebeck coefficient. Graphical abstract: Highlights: We demonstrate an enhancement of thermoelectric properties by creating γ-SbTe/Sb2 Te3 nanocomposite film, where γ-SbTe nanoinclusions are embedded in a nanocrystalline Sb2 Te3 matrix. The formation of the γ-SbTe is attributed to the different enthalpies of mixing for the bonding structures available in the Sb–Te system. The two-phase system provided the carrier energy filtering effect at the interfaces between two phases, leading to enhanced Seebeck coefficient without affecting its electrical transport properties. The band bending at the two-phase interfaces was indirectly manifested by measuring the difference in the valence band (90 meV), advocating the possibility of a strong energy-dependent charge scattering.