1303.3846 (ZhenHua Wang et al.)

Ambipolar Surface Conduction in Ternary Topological Insulator
Bi_2(Te_{1-x}Se_x)_3 Nanoribbons    [PDF]

ZhenHua Wang, Richard L. J. Qiu, Chee Huei Lee, ZhiDong Zhang, Xuan P. A. Gao

We report the composition and gate voltage induced tuning of transport properties in chemically synthesized Bi2(Te1-xSex)3 nanoribbons. It is found that increasing Se concentration effectively suppresses the bulk carrier transport and induces semiconducting behavior in the temperature dependent resistance of Bi2(Te1-xSex)3 nanoribbons when x is greater than ~10%. In Bi2(Te1-xSex)3 nanoribbons with x ~20%, gate voltage enables ambipolar modulation of resistance (or conductance) in samples with thickness around or larger than 100nm, indicating significantly enhanced contribution in transport from the gapless surface states.

View original: http://arxiv.org/abs/1303.3846