Faculty Mentor – Dr. Mary Ellen Zvanut
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.