材料科学
掺杂剂
铜
合金
热电效应
冶金
原子单位
比例(比率)
纳米技术
兴奋剂
光电子学
热力学
量子力学
物理
作者
Yongsun Kim,K. S. Lee,Lan Fu,Minseok Oh,S. Yang,S. Ning,G.C. Han,M. J. Kim,Jung-Hyun Kim,M. S. Jeong,Jason S.C. Jang,E. Lee,Eiji Okunishi,Hirotaka Sawada,Si Wouk Kim,S. J. Pennycook,Yen-Jie Lee,S. H. Kim
标识
DOI:10.1016/j.mtphys.2021.100347
摘要
Abstract Elemental doping is a universal strategy in controlling the functionalities of materials that strongly correlate with naturally formed atomic defects. Element-resolved chemical mapping for atomic defects has answered numerous problems on the relations between defective structures and properties. However, tracking small amounts of dopants in multicomponent bulks and clarifying their doping behaviors remain challenging. Using advanced X-ray spectroscopy, the excess Cu doping behavior in ternary Bi2Te2·7Se0.3 bulk alloy is visualized with the unprecedented detectability from sub-one atomic percent of concentration. The low content of 0.2 at.% Cu preferentially occupies the Bi site, while Cu atoms are found in three crystallographic sites of Bi2Te3 structure and van der Waals gap at high Cu content of 1.2 at.%. These behaviors explain the nontrivial role of Cu dopants on carrier generation processes and relevant thermoelectric properties of Bi2Te2·7Se0.3. The atomic-level identification should also stimulate the elucidation of diverse properties in doped nanomaterials and quantum phenomena in doped topological insulators.
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