CAREER: Optical and Phonon Interactions in Wide-Bandgap Nano-Structures Grant uri icon



  • This CAREER project addresses optical properties/interactions and phonon dynamics of wide band gap semiconductor nanostructures capable of light emission in the UV range utilizing Raman and photoluminescence spectroscopy. Wide bandgap semiconductors to be investigated include GaN, AlN, and AlGaN alloys, as well as ZnO, and SiC. Research issues concerning light emission, crystal structure and crystal symmetry characteristics of nano-particles, quantum-dots, and random-structured powders will be studied. The approach includes the study of properties of individual nanocrystals as well as ensembles of particles to explore the basic mechanisms of light emission properties such as spectral range and efficiency inherent to a confined structure of a given size and shape, as well as the impact of the cluster environment. Additionally, energy re-laxation channels which occur via crystal vibrational modes--electron-phonon interactions, will be investigated to assess the impact of confined phonons on optical characteristics of particles. Year 1 of the project is focused on investigation of optical and material properties of nano-structures of SiC, GaN, AlN, ZnO, to lay the foundation for the study of more complicated mixed particle systems in the following years. Years 2 and 3 will focus on studies concerning the optical properties of particle ensembles and clusters and on establishing a novel UV-optical spectroscopy setup for remote excitation to enable studies concerning phenomena of light interactions, energy transfer, exciton diffusion, and efficiency losses among nano-particles. Years 4 and 5 will focus on resonant Raman scattering studies, as well as research involving the optical and structural behavior of nanostructures under high-pressure, high-temperature conditions.
    The project addresses fundamental materials science research issues having technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. In tandem with the research program, new interdisciplinary curricula will be developed including a new course on optical materials and devices and a new undergraduate degree program on the Science of Materials. The course curriculum will be designed for upper level undergraduate students as well as for graduate students from various science disciplines. This program will focus on a broad spectrum of issues related to materials science, physics, and the chemistry of materials from the large scale to the molecular level. The impact of the proposed research will be to contribute towards basic knowledge of the structural and optical characteristics of nanocrystallites, a key to engineering viable optical devices operating in the UV. The new curricula, together with the active promotion of student participation in experimental research, is expected to have broad impact on the educational development of students and in the longer term contribute to both high technology industry and academia.

date/time interval

  • March 1, 2003 - December 31, 2008

total award amount

  • 393,626