Direct growth of compound semiconductor nanowires by on-film formation of nanowires: bismuth telluride.

Ham, Jinhee; Shim, Wooyoung; Kim, Do Hyun; Lee, Seunghyun; Roh, Jongwook; Sohn, Sung Woo; Oh, Kyu Hwan; Voorhees, Peter W et al. · Nano Lett · 2009

basic_science · Level V

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Abstract

Bismuth telluride (Bi(2)Te(3)) nanowires are of great interest as nanoscale building blocks for high-efficiency thermoelectric devices. Their low-dimensional character leads to an enhanced figure-of-merit (ZT), an indicator of thermoelectric efficiency. Herein, we report the invention of a direct growth method termed On-Film Formation of Nanowires (OFF-ON) for making high-quality single-crystal compound semiconductor nanowires, that is, Bi(2)Te(3), without the use of conventional templates, catalysts, or starting materials. We have used the OFF-ON technique to grow single crystal compound semiconductor Bi(2)Te(3) nanowires from sputtered BiTe films after thermal annealing at 350 degrees C. The mechanism for wire growth is stress-induced mass flow along grain boundaries in the polycrystalline film. OFF-ON is a simple but powerful method for growing perfect single-crystal compound semiconductor nanowires of high aspect ratio with high crystallinity that distinguishes it from other competitive growth approaches that have been developed to date.