期刊
NANO LETTERS
卷 10, 期 4, 页码 1209-1218出版社
AMER CHEMICAL SOC
DOI: 10.1021/nl903590b
关键词
Bismuth telluride; 2D crystals; atomically thin Films; thermoelectrics; topological insulators; graphene-like exfoliation
类别
资金
- DARPA-SRC
- Interconnect Focus Center (IFC)
- US AFOSR [A9550-08-1-0100]
Bismuth telluride (Bi2Te3) and its alloys are the best bulk thermoelectric materials known today. In addition, stacked quasi-two-dimensional (2D) layers of Bi2Te3 were recently identified as promising topological insulators. In this Letter we describe a method for graphene-inspired exfoliation of crystalline bismuth telluride Films with a thickness of a few atoms. The atomically thin Films were suspended across trenches in Si/SiO2 substrates, and subjected to detail material characterization, which included atomic force microscopy and micro-Raman spectroscopy. The presence of the van der Waals gaps allowed us to disassemble Bi2Te3 crystal into its quintuple building blocks five monatomic sheets consisting of Te-(1)-Bi-Te-(2)-Bi-Te-(1). By altering the thickness and sequence of atomic planes, we were able to create designer nonstoichiometric quasi-2D crystalline Films, change their composition and doping, the type of charge carriers as well as other properties. The exfoliated quintuples and ultrathin Films have low thermal conductivity, high electrical conductivity, and enhanced thermoelectric properties. The obtained results pave the way for producing stacks of crystalline bismuth telluride quantum wells with the strong spatial confinement of charge carriers and acoustic phonons, beneficial for thermoelectric devices. The developed technology for producing free-standing quasi-2D layers of Te-(1)-Bi-Te-(2)-Bi-Te-(1) creates an impetus for investigation of the topological insulators and their possible practical applications.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据