TECHNICAL EXPLANATION This project addresses fundamental optical properties of high quality single crystals of a group of organic semiconductors-oligoacenes and their derivatives (including rubrene). These materials are the subject of intense development for use in device applications, but most measurements to date have been on thin-film devices in which intrinsic properties of the semiconductor have been substantially modified by film deposition and device processing. The approach is to use Raman scattering, photoluminescence, and optical absorption at varying temperature, pressure, and excitation energy to measure the optical properties of single crystals of oligoacenes and related materials, and their dependence on characteristics such as number of rings and intermolecular spacing. Additionally, computational modeling will be used to help assess the origin of observed properties, and to predict properties of related compounds. The combination of these two efforts (experimental and theoretical) is expected to lead to greater understanding of the relationship of intrinsic optical and electronic properties of these materials to their molecular and crystal structure. The project is collaborative with Christian Kloc of Lucent Technologies. Dr. Kloc and his co-workers are engaged in an active program of development of organic materials for electronic device applications, and are growing a wide variety of crystals whose properties (e.g. mobility) make them potential candidates for such applications. NON-TECHNICAL EXPLANATION The project addresses fundamental materials research with strong technological relevance to electronics and photonics, and effectively integrates research and education. The impact of the project includes education of the next generation of scientists with active PI emphasis on broadening participation of underrepresented groups. The students who participate in this project will develop not only advanced skills in characterization and spectroscopy, but also (through their direct collaboration with Dr. Kloc in the crystal growth) a deeper understanding of materials fabrication, helping them to be well prepared upon completion of their degrees to make significant contributions in the interdisciplinary environment found in today's leading industrial research and development facilities. Through the Summer Pre-Graduate Research Experience program at UNC-CH, the PI will bring students from underrepresented minorities into her laboratory to participate in the research activities and gain some of these same benefits.
