Millimeter-Long Silicon Nanowires with Uniform Electronic Properties

Abstract

One-dimensional semiconductor nanowires have attracted increasing interest due to their potential device applications as well as novel physical properties. In particular, ultralong nanowires whose lengths go over macroscopic length scales and reach the size of integrated systems, would be the unique building blocks that interlink the nanometer-scale world with the real macroscopic world. This talk describes the approach to synthesize the millimeter-long silicon nanowires (SiNWs) by accelerating the rate-limiting step in vapor-liquid-solid (VLS). Quantitative analysis showed that the average length of 1-hour grown SiNWs is ~1.8 mm, and that the longest ones reach 3.5 mm while the diameters are uniform along the wires. In addition, boron doped, p-type SiNWs exhibited the uniform electrical properties along the entire length of wires and this electronic uniformity of millimeter-long SiNWs was further exploited to demonstrate the complex electronic circuits and multiplexed biological sensor array by the direct integration of a large number of device elements into a single wire. The detailed growth mechanism for the millimeter-long SiNWs will also be discussed.