PEER Project Descriptions: Summer 2005
1.
Dielectric Passivation of High Temperature SiC Power Diodes
Prof.
R. D. Vispute (Physics, UMCP) and Aivars Lelis (ARL)
Our current research activites under the PEER are focused on wide bandgap (WBG) semiconductors (particularly SiC) and related materials, their processing, and the successful passivation of WBG power electronics devices, including diodes and transistors, using alternative dielectric films such as AlN. This work involves understanding how to deposit these dielectric films and analyze their quality using various diagnostic tools.
2.
Efficient Generation of Terahertz Pulses from InN via Optical Pumping at 1.55 mm
Dr. Thomas Murphy (EE, UMCP)
and Mick Warback (ARL)
Indium nitride (InN) and indium gallium nitride (InGaN) are promising materials for optoelectronic applications such as high efficiency conversion of near infrared optical pulses to submillimeter wave pulses with bandwidth in the terahertz frequency range. This project entails the optical and electrical study of polarization- and strain-induced electric fields in n-InN epilayers and InN/InGaN multiple quantum wells to determine their suitability for use as terahertz radiation emitters under femtosecond pulse excitation.
3.
Low-cost, High-efficiency InGaN/Si Solar Cells for Solar Power and Energy
Prof.
Mario Degenais (EE, UMCP) and Mike Warback (ARL)
Indium nitride (InN) and indium gallium nitride (InGaN) are promising materials for optoelectronic applications such as high efficiency full-spectrum solar cells. This project focuses on the optical and electrical characterization of InGaN grown by molecular beam epitaxy and InN sputter deposited on amorphous Si for high efficiency and flexible solar cells.
4.
Materials Processing Characterization and Removal of Defects in Ion Implanted SiC and GaN
Prof.
T. Venkatesan (EE, UMCP) and Dr. K. Jones (ARL)
Work is being done on the wide bandgap semiconductors, SiC and GaN, to improve their p-type conductivity for application to high power -high temperature devices in hybrid electrical vehicles, and to better control their n-type conductivity with application to high power - high frequency devices used in radar systems. This is done by studying ion implantation activation using a number of electrical and optical techniques. We are also looking at ways to grow p-type material in selected areas to replace some of the ion implanted structures.
5.
Modeling and Simulation of 4H SiC Mosfets as a Function of Temperature
Prof.
N. Goldsman (EE, UMCP), Aivars Lelis (ARL), & Bruce Geil (ARL)
SiC is a wide bandgap semiconductor material with many beneficial material qualities vis-à-vis silicon that makes it attractive for high-temperature and high-power applications. In addition, because of its ability to grow thermal SiO2, SiC MOSFETs can be readily manufactured, leading to the potential availability of high-power voltage-controlled switches and high-temperature MOS-based logic. The goal of this project is to successfully model 4H SiC MOSFETs as a function of temperature by properly accounting for the device physics controlling device behavior. This requires careful measurement and analysis of actual devices as a function of bias and temperature.
6.
Semiconducting Nanotube and Organic Nanowire Transistors
Prof.
Michael S. Fuhrer (Physics, UMCP) and Dr. Alma E. Wickenden (ARL)
Research intended to stimulate the development of nanoscale electronic circuits and novel sensor technologies is being conducted for applications including electronic textiles and low power ultraminiaturized chemical/biological sensors. Semiconducting carbon nanotubes are being grown at UMD and are being investigated for high speed field-effect transistors. Nanoelectronics test architectures are being developed within ARL's Class 10/100 cleanroom facility, using in-house electron beam lithography and nanofabrication capabilities. This research project, based on joint efforts between UMD and ARL, will investigate the fundamental transport properties of nanoscale electronic structures, including carbon nanotubes, electrospun polyaniline nanofibers, and/or inorganic semiconducting nanowires. Experimental efforts include I/V and C/V evaluation of metallized contacts to nanofibers, -tubes, and -wires, and the investigation of electron/hole transport in the nanoelectronic structures as a function of temperature and ambient environment. Physical characterization of nanostructures using scanning electron microscopy and atomic force microscopy is envisioned, and the design of electronic circuits integrating nanoscale active components is within the scope of this research.