Technical: This project aims for greater understanding of the microstructure and properties of dilute nitride-bismide semiconductor alloy heterostructures. The project is interdisciplinary and collaborative among investigators at U-Michigan, U-Notre Dame, U-College Cork, and the Tyndall Institute (Ireland). A primary objective is to identify and understand synthesis/processing mechanisms along with conditions needed to manipulate the microstructure and consequent electronic states and optical emission efficiencies of these materials. Dilute nitride-bismide alloy films will be synthesized using plasma-assisted molecular-beam epitaxy, using both amphoteric (group IV) and alternative (group VI) dopants. The microstructure will be tailored using a novel approach to seed compositional patterns using pre-growth focused-ion-beam implantation. The atomic-to-nanometer-scale structure will be determined using state-of-the-art microscopic and spectroscopic techniques. These results will be interpreted using a complementary set of computational studies, including density functional theory, tight-binding calculations, and effective-mass based calculations.
The project addresses basic research issues in a topical area of materials science with technological relevance in electronics and photonics. The scientific insights from this project are expected to enable the development of temperature-insensitive light-emitters, high efficiency photovoltaics, and high performance transistors to be used in the telecommunications, radar, and automotive industries. Graduate, undergraduate, and high school students will benefit from working together in an interdisciplinary scientific learning environment across disciplines of chemistry, physics, and engineering. The established collaboration constitutes an advantageous approach, benefitting from the complementary expertise of investigators covering theory and experiment. The new knowledge created will be broadly disseminated through publications and presentations. Outreach activities will emphasize the mentoring of women and underrepresented minorities.
