Jeong S. Moon

AlGaN/GaN heterojunction field effect transistors grown by nitrogen plasma assisted molecular beam epitaxy

In this work, we demonstrate state of the art performance of GaN HFETs grown on SiC by rf Nitrogen plasma assisted molecular beam epitaxy (MBE) at 10 and 20 GHz and good power scalability of these devices at 10 GHz. A single stage power amplifier built by power combining four of our 1 mm devices exhibits continuous wave output power of 22.9 W with associated power added efficiency (PAE) of 37% at 9 GHz. This is to the best of our knowledge the highest CW power and the best combination of power and PAE demonstrated to date for a GaN based microwave integrated circuit at this frequency.

Rashba effect resonant tunneling spin filters

We propose an InAs/GaSb/AlSb-based asymmetric resonant interband tunneling diode (a-RITD) as a spin filter. The device exploits the Rashba effect to achieve spin polarization under zero magnetic field using nonmagnetic III-V semiconductor heterostructures. We discuss the basic principles of the interband tunneling spin filter, and present modeling results that demonstrate its advantage. We also propose an implementation procedure for realizing device structure.

Room-temperature InAlAs∕InGaAs∕InP planar resonant tunneling-coupled transistor

We report an experimental demonstration of room-temperature InAlAs∕InGaAs∕InP planar two-dimensional to two-dimensional resonant tunneling-coupled transistors, in which the tunneling characteristics such as negative differential resistance and peak current are controlled by a surface Schottky gate similar to the state-of-the-art high-electron-mobility transistors (HEMT) with high gain. The tunneling peak voltage was modulated linearly with the Schottky gate voltage with a ratio of nearly unity. Functionality of the device can also be switched between HEMT and tunneling transistor mode. The fabrication process is fully compatible with conventional HEMT processes, offering a fully integrable and scalable tunneling transistor technology.

Development of GaN-based micro chemical sensor nodes

Sensors based on III-N technology are gaining significant interest due to their potential for monolithic integration of RF transceivers and light sources and the capability of high temperature operations. We are developing a GaN-based micro chemical sensor node for remote detection of chemical toxins, and present electrical responses of AlGaN/GaN HEMT (high electron mobility transistor) sensors to chemical toxins as well as other common gases. Upon exposure to a chemical toxin, the sensor showed immediate increase in source-drain current (Ids). The electrical response of the sensor was clear, reproducible and characteristic of the concentration of the analyte. This is the first time that electrical responses of chemical toxins are measured with a GaN-based microsensor. Detailed analysis on response time, sensitivity and temperature dependence will be discussed

K-band GaN power HFET's with 6.6 W/mm CW saturated output power density and 35% power added efficiency at 20 GHz

AlGaN/GaN heterostructure field effect transistors (HFETs) grown on SiC substrates are currently the most powerful three-terminal microwave solid state devices. While the power performance of these devices is well documented at X-band frequencies, there is growing interest in these devices at higher frequencies. In this study we characterize the power performance of GaN HFETs at 20 GHz. Our results clearly show that GaN HFETs have strong potential for power applications at K-band frequencies and beyond.

High-Speed Graphene Field Effect Transistors on Microbial Cellulose Biomembrane

For the goal of developing biocompatible sensors and electronics for <italic>in vivo</italic> applications, we report the first graphene field effect transistors (GFETs) fabricated on microbial cellulose (MBC), a biointegrative and ultraflexible biopolymer membrane. GFETs on MBC are fabricated in a wafer-scale using a transferred CVD graphene with a mobility of <inline-formula><tex-math notation=LaTeX>

Graphene based active and passive component development on transparent substrates

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Study on Large-signal Linearity and Efficiency of AlGaN/GaN MODFETs

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Silver Nanowire-Based Infrared-Transparent Contacts for Future High-Density Format Focal Plane Arrays

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Arrays of Nano Tunnel Junctions as Infrared Image Sensors

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