Publications

Results 51–75 of 86

Search results

Jump to search filters

Highly Efficient Solar-Blind Single Photon Detectors

Armstrong, Andrew A.; Klein, Brianna A.; Allerman, A.A.; Baca, Albert G.; Crawford, Mary H.; Pickrell, Gregory W.; Perez, Carlos; Podkaminer, Jacob; Siegal, Michael P.; Jayawardena, Asanka; Ahyi, Ayayi; Dhar, Sarit

Photodetectors sensitive to the ultra-violet spectrum were demonstrated using an AlGaN high electron mobility transistor with an GaN nanodot optical floating gate. Peak responsivity of 2 x 109 A/W was achieved with a gain-bandwidth product > 1 GHz at a cut-on energy of 4.10 eV. Similar devices exhibited visible-blind rejection ratios > 106. The photodetection mechanism for $β$-Ga2O3 was also investigated. It was concluded that Schottky barrier lowering by self-trapped holes enables photodetector gain.

More Details
TYPE SAND Report YEAR 2018
DOIOSTI

Al0.85Ga0.15N/Al0.70Ga0.30N High Electron Mobility Transistors with Schottky Gates and Large On/Off Current Ratio over Temperature

ECS Journal of Solid State Science and Technology

Baca, Albert G.; Klein, Brianna A.; Allerman, A.A.; Armstrong, Andrew A.; Douglas, Erica A.; Stephenson, Chad A.; Fortune, Torben; Kaplar, Robert

AlGaN-channel high electron mobility transistors (HEMTs) are among a class of ultra wide-bandgap transistors that are promising candidates for RF and power applications. Long-channel AlxGa1-xN HEMTs with x = 0.7 in the channel have been built and evaluated across the -50°C to +200°C temperature range. These devices achieved room temperature drain current as high as 46 mA/mm and were absent of gate leakage until the gate diode forward bias turn-on at ~2.8 V, with a modest -2.2 V threshold voltage. A very large Ion/Ioff current ratio, of 8 × 109 was demonstrated. A near ideal subthreshold slope that is just 35% higher than the theoretical limit across the temperature range was characterized. The ohmic contact characteristics were rectifying from -50°C to +50°C and became nearly linear at temperatures above 100°C. An activation energy of 0.55 eV dictates the temperature dependence of off-state leakage.

More Details
TYPE Journal Article YEAR 2017
DOIOSTI
Results 51–75 of 86
Results 51–75 of 86