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conferenceseries
.com
Volume 4, Issue 4 (Suppl)
J Laser Opt Photonics, an open access journal
ISSN: 2469-410X
Optics 2017
November 15-17, 2017
November 15-17, 2017 | Las Vegas, USA
8
th
International Conference and Exhibition on
Lasers, Optics & Photonics
Heterojunction detectors for multi-band detection with wavelength threshold extension mechanism
A G Unil Perera
Georgia State University, USA
M
ulti-band photodetectors have received increased attention over the years due to their wide applications in civilan, commercial,
medical and military sectors. The photodetectors based on III-V semiconductor heterostructures have been studied extensively
for multi-band detection, covering ultra-violet (UV) to far-infrared (FIR) region. Due to material system maturity, GaAs/Al
x
Ga
1-x
As
heterostructures provide an attractive option demonstrating photodetection covering UV-FIR range. In more recent studies, the
conventional spectral threshold limit, that is, λ
t
=hc/Δ set by the minimum energy gap Δ, has been overcome owing to a novel detection
mechanism arising from the hot-carrier effect in the asymmetrical p-GaAs/Al
x
Ga
1-x
as heterostructures. It has been experimentally
demonstrated that a detector with a conventional spectral threshold of ~3.1 µm shows an extended wavelength threshold of up to ~68
µm. In addition to the munti-band detection capability, an important advantage of the wavelength extension mechanism is a lower
dark current of the dectctor, which is determined by standard Δ and is evident from close agreement of the experimentally measured
dark current data to the theoretical fits based on 3D carrier drift model. Therefore, the wavelength threshold extension mechanism
makes it possible to design a detector with its dark current being much lower compared to that of a detector without the extension
mechanism. Based on the these studies, the of III-V semiconductor heterostructures offer potential for multi-band detection from
UV to FIR by utilizing appropriate detector architectures.
Biography
A G Unil Perera has received the BS degree in Physics (with first class honors) from the University of Colombo, Colombo, Sri Lanka and an MS and PhD degrees from the
University of Pittsburgh. He is currently a Regents’ Professor at the Department of Physics and Astronomy, Georgia State University, Atlanta. He is a Fellow of the IEEE,
SPIE and APS. He has 8 US patents, 4 edited books, 11 invited book chapters and over 180 publications. He is also a Member of the Editorial Board for the
IEEE Journal
of Electron Device Society.
uperera@gsu.eduA G Unil Perera, J Laser Opt Photonics 2017, 4:4 (Suppl)
DOI: 10.4172/2469-410X-C1-017