The focus of this research is the investigation
of materials with potential applications in micro- and opto-electronics.
The student could work on either electrical or materials
characterization. The former involves techniques such as optical
admittance spectroscopy. The latter includes electron paramagnetic
resonance (EPR) or surface profilometry. Either project can be tailored
to the level of an undergraduate physics, chemistry, or engineering
student. The program involving electrical characterization will focus on
studying the electronic property of defects in wide band gap
semiconductors that are considered potential substitutes for Si in high
power electronics. The materials to be addressed are responsible for the
latest inventions such as DVD’s and blue LED’s. The REU student will
perform a variety of measurements of capacitance, conductance, and
current-voltage. He/she will test the effects of annealing in different
ambients and compare results to those obtained using other techniques.
An alternative project would involve testing various methods used to
deposit electrical contacts onto the surface of these important new wide
band gap materials. This is an area of research that is critical to the
advancement of the high power electronics effort. The other project
involving materials characterization is to use EPR to measure the
effects of thermal annealing on samples similar to those being studied
electrically. The REU student will have a chance to measure the
influence of these centers on the conductivity of the material and to
learn about their ultimate effect on device operation. Interestingly,
although the material under investigation is a semiconductor, the goal
here is to understand how to make the samples semi-insulating!
All of the studies discussed above are suitable for a college level
student. Interpretation of the electrical data involves nothing more
than undergraduate electricity and magnetism. The EPR projects will be
limited to counting known defects, avoiding the need for complex quantum
mechanical understanding of the data. At various times throughout the
past 5 years, 6 undergraduates and 3 high school students have worked in
Dr. Zvanut's group and resulted in several publications
[9,10]. Ultimately, the research experience should introduce the REU
student to basic electrical measurement techniques, materials
fabrication and analysis, as well as data manipulation and
interpretation. |