Free-Electron-Laser Spectroscopy of Semiconductor Surfaces and Interfaces.
Abstract
The inauguration and long-term successful operation of the Vanderbilt Free-Electron Laser (FEL) has opened up extraordinary opportunities for semiconductor research. The Vanderbilt FEL is continuously tunable over a broad spectral range; this range, easily augmented by frequency multiplication and higher-harmonic operation, covers the band gaps of most of the technologically important semiconductors. The FEL's high average power and peculiar time structure has been exploited in a number of advanced semiconductor spectroscopies that promises to increase our understanding of the electronic structure and dynamic response of these fundamentally interesting and technologically crucial materials. Our program is built on a firm and concrete background, with a record of results that has fulfilled the initial promise involving the systematic use of an FEL in semiconductor and materials research. Significant results have been obtained in two different areas: FEL Internal Photoemission (FELIPE) measurements of interface energy barriers, and two-photon absorption. In the case of FELIPE, the first results, which were also the first FEL data on surfaces or interfaces, concerned heterojunction band discontinuities. This has been for many years a central problem in solid state science, with fundamental and applied aspects.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1993
- Accession Number
- ADA323027
Entities
People
- Giorgio Margaritondo
- Norman H. Tolk
Organizations
- Vanderbilt University