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Journal of Nanomaterials
Volume 2012 (2012), Article ID 452310, 5 pages
http://dx.doi.org/10.1155/2012/452310
Research Article

GaN Schottky Diode with TiW Electrodes on Silicon Substrate Based on AlN/AlGaN Buffer Layer

Institute of Microelectronics & Department of Electrical Engineering, Center for Micro/Nano Science and Technology, Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan

Received 30 May 2012; Revised 12 November 2012; Accepted 26 November 2012

Academic Editor: Yong Yang

Copyright © 2012 Sheng-Po Chang. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We report the fabrication of GaN Schottky photodiodes (PDs) on Si(111) substrates coated with an AlN/AlGaN buffer multilayer. It was found that their dark current was much smaller than that of identical devices prepared on sapphire substrates. With an incident wavelength of 359 nm, the maximum responsivity of the n-GaN Schottky photodetectors with TiW contact electrodes was 0.1544 A/W, corresponding to a quantum efficiency of 53.4%. For a given bandwidth of 1 kHz and bias of 5 V, the resultant noise equivalent power (NEP) of n-GaN Schottky photodetectors with TiW electrodes was  W, corresponding to a detectivity () of  cm-Hz0.5 W−1.