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Title: Large area, low capacitance, GaAs nanowire photodetector with a transparent Schottky collecting junction

We present experimental results on a GaAs/Indium-Tin-Oxide Schottky-like heterojunction photodetector based on a nanowire device geometry. By distributing the active detecting area over an array of nanowires, it is possible to achieve large area detection with low capacitance. Devices with bare GaAs and passivated AlGaAs/GaAs nanowires are fabricated to compare the responsivity with and without surface passivation. We are able to achieve responsivity of >0.5A/W and Signal-Noise-Ratio in excess of 7 dB for 2 V applied reverse bias with passivated nanowire devices. Capacitance-voltage measurement yields <5 nF/cm{sup 2}, which shows a strong possibility for high-speed applications with a broad area device.
Authors:
; ; ;  [1] ;  [1] ;  [2]
  1. Center for Energy Nanoscience, University of Southern California, Los Angeles, California 90089 (United States)
  2. (NECTAR), Advanced Studies Laboratories, University of California, Santa Cruz, California 95064, USA and NASA Ames Research Center, Moffett Field, California 94035 (United States)
Publication Date:
OSTI Identifier:
22253708
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 25; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; ALUMINIUM ARSENIDES; CAPACITANCE; GALLIUM ARSENIDES; HETEROJUNCTIONS; INDIUM; QUANTUM WIRES; SIGNAL-TO-NOISE RATIO; TIN OXIDES