Transport in single InAs Nanowire and Bi2Se3 Flake Photosensitive Devices*

We report on preliminary measurements of devices fabricated from single InAs nanowires and exfoliated Bi2Se3 flakes. The Wurtzite InAs nanowires were mechanically harvested from the MOCVD-grown substrates and dispersed onto a Si/SiO2 substrate. The Bi2Se3 flakes were exfoliated from Bi2Se3 single crystals which were grown in a Bridgeman furnace. The 60 to 100 nm thick flakes were dispersed onto a Si/SiO2 substrate. Using photolithography two electrical contacts were defined on either end of the nanowires or flakes by deposition of 20 nm Titanium followed by 300 nm Aluminum. Using a probe station and current amplifier, current-voltage measurements were obtained both in the dark and under white light illumination. Most devices showed I-V behavior consistent with back-to-back Schottky contacts, with some evident photosensitivity under illumination.