L. S. CHUAH^1,* , Z. HASSAN¹, H. ABU HASSAN¹

Abstract

The feasibility in reducing the dark current of the metal-semiconductor-metal (MSM) photodetector was investigated by the adoption of porous AlGaN layer. High quality unintentionally doped n-type Al0.09Ga0.91N films were grown on Si(111) with AlN as buffer layer using radio frequency (RF) nitrogen plasma-assisted molecular beam epitaxy (MBE). Porous AlGaN in this work was generated by Pt assisted electroless etching. Two narrow stripes of Pt with thickness of about 300 nm were deposited on the AlGaN sample by using sputtering system. The samples were then etched in a solution of 4:1:1 HF:CH3OH:H2O2 under illumination of an UV lamp with 500 W power for 15 minutes. From the literature, the use of porous AlGaN layer for dark current reduction has not been reported. In addition, the process involved in the fabrication of device was simple and required no expensive equipment. The I-V characteristics of as grown and porous Ni/AlGaN MSM photodetectors under dark and Hg lamp illumination conditions were recorded. The porous sample showed a significantly low dark current at 3V as compared to as grown sample, the dark current of porous sample was about three orders of magnitudes smaller than as grown sample. When the sample was under Hg lamp illumination condition, the change of current was significant for porous sample as compared to the as grown sample..

Keywords

AlGaN, Porous, MSM, Si, UV-photodetector.

Submitted at: May 29, 2007
Accepted at: Sept. 18, 2007

Citation

L. S. CHUAH, Z. HASSAN, H. ABU HASSAN, Dark current characteristics of Ni contacts on porous AlGaN-based UV photodetector, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 9, pp. 2886-2890 (2007)

• Download Fulltext
• Downloads: 172 (from 159 distinct Internet Addresses ).

• Scientometry
• Fast publication
• Old Site

• journals@inoe.ro
• (+40) 021-457 57 58
• (+40) 021-457 45 22
• 409 Atomistilor Str.
  077125 Magurele,
  Ilfov, Romania