Accession Number : ADA323027

Title :   Free-Electron-Laser Spectroscopy of Semiconductor Surfaces and Interfaces.

Descriptive Note : Final technical rept.,

Corporate Author : VANDERBILT UNIV NASHVILLE TN DEPT OF PHYSICS AND ASTRONOMY

Personal Author(s) : Margaritondo, Giorgio ; Tolk, Norman H.

PDF Url : ADA323027

Report Date : 1993

Pagination or Media Count : 8

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.

Descriptors :   *SPECTROSCOPY, *INTERFACES, *SEMICONDUCTORS, *SURFACES, *FREE ELECTRON LASERS, FREQUENCY, ELECTRONICS, TUNABLE LASERS, MATERIALS, HETEROJUNCTIONS, DYNAMIC RESPONSE, ENERGY, AUGMENTATION, HARMONICS, ENERGY GAPS, CONCRETE, PHOTOELECTRIC EMISSION, INTERNAL, BARRIERS, TWO PHOTON ABSORPTION, SOLID STATE PHYSICS, MULTIPLICATION.

Subject Categories : Electrical and Electronic Equipment
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE