Near-Infrared Photoresponse in Photon-Triggered Nanowire Transistors

We investigated a photon-triggered nanowire transistor with near-infrared spectral photoresponse. To understand the mechanism of operation of the nanowire transistor consisting of crystalline Si and porous Si segments, we performed a qualitative analysis of trapped carriers in the porous Si and modeling of a transistor operated by photon gating. We then fabricated a photon-triggered transistor device with a nanowire diameter of 200 nm and a porous Si length of 400 nm. Systematic measurements and analyses demonstrate that the wavelength dependence of the photon-triggered current generation is caused by a broad range of energy levels for the localized trap states of the porous Si segment. We believe that these results pave the way for simplification of the fabrication and operation of ultracompact nanoprocessors and development of efficient nanoscale photodetectors for high-resolution imaging.