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The shift of the threshold voltage Vth in Al2O3/InAlN/GaN metal–oxide–semiconductor high-electron-mobility transistors (MOSHEMTs) is demonstrated by CF4 plasma treatments. The accompanying channel mobility degradation is monitored to understand the tradeoff design space. The effective negative charge introduced by the F plasma treatments at the oxide(More)
We demonstrate a graphene-based electro-absorption modulator achieving extraordinary control of terahertz reflectance. By concentrating the electric field intensity in an active layer of graphene, an extraordinary modulation depth of 64% is achieved while simultaneously exhibiting low insertion loss (∼2 dB), which is remarkable since the active region of(More)
In this paper we propose and experimentally demonstrate arrays of graphene electro-absorption modulators as electrically reconfigurable patterns for terahertz cameras. The active element of these modulators consists of only single-atom-thick graphene, achieving a modulation of the THz wave reflectance > 50% with a potential modulation depth approaching(More)
We propose and discuss terahertz (THz) electro-absorption modulators based on graphene plasmonic structures. The active device consists of a self-gated pair of graphene layers, which are patterned to structures supporting THz plasmonic resonances. These structures allow for efficient control of the effective THz optical conductivity, thus absorption, even(More)
In this letter, we present AlGaN/GaN lateral Schottky barrier diodes on silicon with recessed anodes and dual field plates. A low specific ON-resistance RON,SP (5.12 m ·cm2), a low turn-ON voltage (<0.7 V), and a high reverse breakdown voltage (BV) (>1.9 kV) were simultaneously achieved in devices with a 25-μm anode/cathode distance, resulting in a power(More)
p-n diodes with avalanche breakdown Zongyang Hu, Kazuki Nomoto, Bo Song, Mingda Zhu, Meng Qi, Ming Pan, Xiang Gao, Vladimir Protasenko, Debdeep Jena, and Huili Grace Xing School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853, USA Department of Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556,(More)
Molecular beam epitaxy grown GaN p-n vertical diodes are demonstrated on single-crystal GaN substrates. A low leakage current <3 nA/cm is obtained with reverse bias voltage up to !20 V. With a 400 nm thick n-drift region, an on-resistance of 0.23 mX cm is achieved, with a breakdown voltage corresponding to a peak electric field of "3.1 MV/cm in GaN.(More)
We report vertical GaN-on-GaN p-n diodes with a breakdown voltage (BV) of 1.7 kV and a low differential specific ON-resistance RON of 0.55 m · cm2 with current spreading considered (or 0.4 m · cm2 using the diode bottom mesa size), resulting in a figure-of-merit (V 2 B /RON) of 5.3 GW/cm2 (or 7.2 GW/cm2). These devices exhibit a current swing over 14 orders(More)
AlGaN/GaN high-electron-mobility transistors (HEMT) have been grown by radio frequency molecular beam epitaxy (RF-MBE) on 3” Si substrates. A record low contact resistance Rc ~ 0.11 .mm has been achieved for GaN HEMTs on Si by using non alloyed ohmic contacts regrown by MBE. Owing to the low contact resistance a 75-nm gate length unpassivated HEMT shows(More)