Comparison of ultraviolet APDs grown on free-standing GaN and sapphire substrates

Erdem Cicek, Zahra Vashaei, Can Bayram, Ryan P McClintock, Manijeh Razeghi*, Melville P Ulmer

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


There is a need for semiconductor-based ultraviolet photodetectors to support avalanche gain in order to realize better performance andmore effective compete with existing technologies. Wide bandgap III-Nitride semiconductors are the promising material system for the development of avalanche photodiodes (APDs) that could be a viable alternative to current bulky UV detectors such as photomultiplier tubes. In this paper, we review the current state-of-the-art in IIINitride visible-blind APDs, and present our latest results on GaN APDs grown on both conventional sapphire and low dislocation density free-standing c- and m-plane GaN substrates. Leakage current, gain, and single photon detection efficiency (SPDE) of these APDs were compared. The spectral response and Geiger-mode photon counting performance of UV APDs are studied under low photon fluxes, with single photon detection capabilities as much as 30% being demonstrated in smaller devices. Geiger-mode operation conditions are optimized for enhanced SPDE.

Original languageEnglish (US)
Title of host publicationDetectors and Imaging Devices
Subtitle of host publicationInfrared, Focal Plane, Single Photon
StatePublished - Oct 25 2010
EventDetectors and Imaging Devices: Infrared, Focal Plane, Single Photon - San Diego, CA, United States
Duration: Aug 4 2010Aug 5 2010


OtherDetectors and Imaging Devices: Infrared, Focal Plane, Single Photon
CountryUnited States
CitySan Diego, CA


  • APD
  • Avalanche photodiode
  • GaN
  • Geiger Mode
  • Polar and nonpolar GaN substrates
  • Single photon detection

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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