Mid-Infrared Induced Energy Transfers in Si:Er
Abstract
Excitation and de-excitation mechanisms responsible for photoluminescence of Er(3+) ion in crystalline silicon were investigated by a variety of experimental techniques. Special emphasis was on the two-color time-resolved spectroscopy in the mid-infrared performed at a free-electron laser facility. Application of this technique for spectroscopic investigations of energy transfers within the Si:Er system has been originally proposed and developed in the team of the Principal Investigator. This unique experimental approach revealed that optical excitation of Er(3+) ion is a sequential two-stage process. Localization of a secondary particle, with a subsequent electron-pair recombination and energy transfer to the 4f-electron core, requires a prior capture of a primary particle by a local potential at an Er-related optically active center. Such a process is similar to exciton binding at isoelectronic centers. Consequently, optical properties of a silver dopant representing this class of defects were investigated. In addition to the above, also more classical experimental techniques were used. Excitation spectroscopy in the infrared showed that Er-related emission at lambda 1.5 micrometers could be induced by photons with energies significantly lower than the bandgap of Si. Finally, by magneto-optical spectroscopy symmetry of the Er-related optical center dominant MBE-grown selectively Er-doped Si structures was found to be orthorhombic. In this was microscopic information on the structure of an optically active Er-related center in Si has been obtained in the most direct way.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 16, 2001
- Accession Number
- ADA396783
Entities
People
- Tom Gregorkiewicz
Organizations
- University of Amsterdam