Disordered stoichiometric nanorods and ordered off-stoichiometric nanoparticles in n-type thermoelectric Bi2Te2.7Se0.3
Year: 2012
Type: article
Abstract: N-type Bi2Te2.7Se0.3 bulk thermoelectric materials with peak ZT values up to ∼1 were examined by transmission electron microscopy and electron diffraction. Two nanostructural features were found: (i) a structural modulation of ∼10 nm, which consisted of nanorods with crystalline and nearly amorphous regions, having the rod axes normal to (0,1,5)-type planes, and wave vector normal to (1,0,10)-type planes and (ii) non-stoichiometric ordered Bi-rich nanoparticles. The presence of the structural modulation was not influenced by the ion milling energy or temperature in this study while the non-stoichiometric ordered nanoparticles were only observed when ion milling at low temperatures and low energy was used. It is proposed that both the structural modulation of ∼10 nm and the presence of non-stoichiometric nanoparticles are responsible for the low lattice thermal conductivity (∼0.6 W/mK) of the Bi2Te2.7Se0.3 bulk thermoelectric materials studied.
Source: Journal of Applied Physics
DOI: 10.1063/1.4759285
Authors: Chris E. Carlton, Chris A. Kuryak, Wei-shu Liu, Zhifeng Ren, Gang Chen, Yang Shao-Horn
Institutions: Massachusetts Institute of Technology, Boston College
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Funder: U.S. Department of Energy
OpenAlex ID: W1984454929