Infrared detection using an InSb nanowire

Bulk indium antimonide (InSb) is an III-V semiconductor compound that is widely used to detect infrared (IR) signal of wavelength from 1 um to 5.5 um. InSb nanowire, with huge exciton Bohr radius and small band gap, has great potential in optoelectronics applications. However, IR detector based on InSb nanowire has never been reported due to the limitation of growth technique and the ambiguity of its detection principle. In this paper, IR detector based on a single InSb nanowire will be introduced. InSb nanowires were grown by a vapor-liquid-solid (VLS) approach using InSb powder source and gold catalyst. Stoichiometric nanowires with diameters in the 10-35 nm range and tens of microns long have been obtained. The structure of the InSb nanowire detector consists of an InSb nanowire connecting an Au and a Cu electrode to form a Schottky photodiode, which can separate the photo-generated electron-hole pairs in order to generate photocurrent. An InSb nanowire IR photodetector with an individual InSb nanowire was demonstrated to detect IR signal at room temperature. High quantum efficiency and low dark current were obtained. The InSb nanowires may become significant building blocks for future nano-optoelectronics.