Local Vibrational Modes of Impurities in Semiconductors

Washington State University, Pullman WA

Investigators

Abstract

This project addresses local vibrational mode (LVM) spectroscopy of semiconductors such as GaN, ZnO, Si, and CdTe in order to determine the structure of defect centers and their vibrational interactions with the host environment. Impurities such as hydrogen, oxygen, and DX centers will be studied in these technologically important materials. Hydrostatic pressure will be used, with infrared (IR) and Raman spectroscopy, to probe the LVMs arising from such impurities. In addition to inorganic semiconductors, organic semiconductors such as pentacene will also be investigated. Time-resolved experiments using ultrafast IR spectroscopy will be used to probe vibrational lifetimes and resonant interactions in semiconductors. The project addresses fundamental research issues in a topical area of electronic/photonic materials science having high technological relevance. An important feature of the project is the strong emphasis on education, and the integration of research and education. The proposed educational activities will benefit a range of students from the eighth grade to graduate school. Educational programs integrated with research include outreach activities with a public school on the Colville Indian reservation, improvements to undergraduate physics courses, and the development of laboratories and lecture demonstrations. These activities are pursued to encourage students from diverse backgrounds to enter fields related to materials science and solid-state physics.