Amir M. Dabiran

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This article reports forward and reverse biased emission in vertical ZnO nanowire/p-GaN heterojunction light emitting diodes (LEDs) grown out of solution on Mg-doped p-GaN films. The electroluminescence spectra under forward and reverse bias are distinctly different. Forward bias showed two peaks centered around 390 nm and 585 nm, while reverse bias showed(More)
This article reports forward and reverse biased emission in vertical ZnO nanowire/p-GaN heterojunction light emitting diodes (LEDs) grown out of solution on Mg-doped p-GaN films. The electroluminescence spectra under forward and reverse bias are distinctly different. Forward bias showed two peaks centered around 390 nm and 585 nm, while reverse bias showed(More)
High electron mobility transistors (HEMT) Tin oxide (SnO 2) Annealing a b s t r a c t In this study, we report on a demonstration of hydrogen sensing at low temperature using SnO 2 functionalized AlGaN/GaN high electron mobility transistors (HEMT). The SnO 2 dispersion was synthesized via a hydrothermal method and selectively deposited on the gate region of(More)
We present the measurements of thermal emittance and response time for a GaN photocathode illuminated with 5 ps pulses at 260 nm wavelength. The thermal emittance was measured downstream of a 100 kV dc gun using a solenoid scan with a wire scanner and a beam viewscreen and was found to be 1.35Ϯ 0.11 mm mrad normalized rms emittance per 1 mm rms of(More)
This paper reports a novel method for producing low ohmic contact resistance, R<inf>c</inf>, as well as low sheet resistance, R<inf>sh</inf>, on AIN/GaN MOS-HEMT structures. The method relies on the protection of the very sensitive A1N epi-layer from exposure to liquid chemicals during processing using evaporated Al, which on thermal oxidation forms(More)
The DC and RF performance of AlGaN/GaN high electron mobility transistors with nanoscale gate lengths is presented. The layer structures were grown by either metal organic chemical vapor deposition or rf plasma-assisted molecular beam epitaxy. Excellent scaling properties were observed as a function of both gate length and width and confirm that these(More)
A comparative assessment of AlGaN/GaN high-electron-mobility transistors (HEMTs) grown by molecular beam epitaxy on silicon and sapphire substrates has been carried out. Large-area power GaN HEMTs with identical device dimensions were fabricated on both substrates. A thicker AlN buffer layer was used for the GaN HEMT on silicon to achieve similar quality(More)
A new method for realising enhancement mode AlGaN/GaN devices using a localized gate-foot oxidation is described. Thermal oxidation of the AlGaN barrier layer converts the top surface/part of this layer into aluminium and gallium oxides, which serve as a good gate dielectric and improve the gate leakage current by several orders of magnitude compared to a(More)
Indium-rich InGaN epitaxial layers with a p-i-n structure were grown pseudomorphically on a strain-relaxed InGaN template to reduce structural strain induced by lattice mismatch. We applied a nano-sculpting process to improve the crystal quality of the strain-relaxed InGaN template. The results show that the nano-sculpting process can suppress effectively(More)
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