Page 24 of 24:  Prev << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24    (581 Items)

1.  State-of-the-art Type II Antimonide-based superlattice photodiodes for infrared detection and imaging
M. Razeghi, B.M. Nguyen, P.Y. Delaunay, E.K. Huang, S. Abdollahi Pour, P. Manurkar, and S. Bogdanov
SPIE Proceedings, Nanophotonics and Macrophotonics for Space Environments II, San Diego, CA, Vol. 7467, p. 74670T-1-- August 5, 2009 ...[Visit Journal]
Type-II InAs/GaSb Superlattice (SL), a system of multi interacting quantum wells was first introduced by Nobel Laureate L. Esaki in the 1970s. Since then, this low dimensional system has drawn a lot of attention for its attractive quantum mechanics properties and its grand potential for the emergence into the application world, especially in infrared detection. In recent years, Type-II InAs/GaSb superlattice photo-detectors have experienced significant improvements in material quality, structural designs and imaging applications which elevated the performances of Type-II InAs/GaSb superlattice photodetectors to a comparable level to the state-of-the-art Mercury Cadmium Telluride. We will present in this talk the current status of the state-of-the-art Type II superlattice photodetectors and focal plane arrays, and the future outlook for this material system. [reprint (PDF)]
 
1.  High quantum efficiency back-illuminated GaN avalanche photodiodes
C. Bayram, J.L. Pau, R. McClintock, M. Razeghi, M.P. Ulmer, and D. Silversmith
Applied Physics Letters, Vol. 93, No. 21, p. 211107-1-- November 24, 2008 ...[Visit Journal]
Back-illuminated avalanche photodiodes (APDs) composed of heterojunctions of either p-GaN/i-GaN/n-AlGaN or p-GaN/i-GaN/n-GaN/n-AlGaN were fabricated on AlN templates. At low voltage, an external quantum efficiency of 57% at 352 nm with a bandpass response was achieved by using AlGaN in the n-layer. Dependency of gain and leakage current on mesa area for these heterojunction APDs were studied. Back-illumination via different wavelength sources was used to demonstrate the advantages of hole-initiated multiplication in GaN APDs. [reprint (PDF)]
 
1.  Overview of Quantum Cascade Laser Research at the Center for Quantum Devices
S. Slivken, A. Evans, J. Nguyen, Y. Bai, P. Sung, S.R. Darvish, W. Zhang and M. Razeghi
SPIE Conference, January 20-25, 2008, San Jose, CA Proceedings – Quantum Sensing and Nanophotonic Devices V, Vol. 6900, p. 69000B-1-8.-- February 1, 2008 ...[Visit Journal]
Over the past several years, our group has endeavored to develop high power quantum cascade lasers for a variety of remote and high sensitivity infrared applications. The systematic optimization of laser performance has allowed for demonstration of high power, continuous-wave quantum cascade lasers operating above room temperature. In the past year alone, the efficiency and power of our short wavelength lasers (~4.8 µm) has doubled. In continuous wave at room temperature, we have now separately demonstrated ~10% wallplug efficiency and ~700 mW of output power. Up to now, we have been able to show that room temperature continuous wave operation with > 100 mW output power in the 3.8 < λ < 11.5 µm wavelength range is possible. [reprint (PDF)]
 
1.  Comparison of type-II superlattice and HgCdTe infrared detector technologies
Jagmohan Bajaj; Gerry Sullivan; Don Lee; Ed Aifer; Manijeh Razeghi
Proc. SPIE 6542, Infrared Technology and Applications XXXIII, 65420B (May 14, 2007)-- May 14, 2007 ...[Visit Journal]
Performance of HgCdTe detector technology surpasses all others in the mid-wave and long-wave infrared spectrum. This technology is relatively mature with current effort focused on improving uniformity, and demonstrating increased focal plane array (FPA) functionality. Type-II superlattice (InAs-GaSb and related alloys) detector technology has seen rapid progress over the past few years. The merits of the superlattice material system rest on predictions of even higher performance than HgCdTe and of engineering advantages. While no one has demonstrated Type-II superlattice detectors with performance superior to HgCdTe detectors, the difference in performance between these two technologies is decreasing. In this paper, we review the status and highlight relative merits of both HgCdTe and Type-II superlattice based detector technologies. [reprint (PDF)]
 
1.  Electroluminescence at 375 nm from a Zn0/GaN:Mg/c-Al2O3 heterojunction light emitting diodes
D.J. Rogers, F.Hosseini Teherani, A. Yasan, K. Minder, P. Kung, and M. Razeghi
Applied Physics Letters, 88 (14)-- April 13, 2006 ...[Visit Journal]
n-ZnO/p-GaN:Mg heterojunction light emitting diode (LED) mesas were fabricated on c-Al2O3 substrates using pulsed laser deposition for the ZnO and metal organic chemical vapor deposition for the GaN:Mg. Room temperature (RT) photoluminescence (PL) showed an intense main peak at 375 nm and a negligibly low green emission indicative of a near band edge excitonic emission from a ZnO layer with low dislocation/defect density. The LEDs showed I-V characteristics confirming a rectifying diode behavior and a RT electroluminescence (EL) peaked at about 375 nm. [reprint (PDF)]
 
1.  High-Power (~9 μm) Quantum Cascade Lasers
S. Slivken, Z. Huang, A. Evans, and M. Razeghi
Virtual Journal of Nanoscale Science and Technology 5 (22)-- June 3, 2002 ...[Visit Journal][reprint (PDF)]
 

Page 24 of 24:  Prev << 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24    (581 Items)