Free-electron laser studies of energy transfer mechanisms in semiconductors doped with transition series ions

• Published in: Journal of luminescence Vol. 94; pp. 243 - 248
• Main Authors: Forcales, M., Klik, M., Vinh, N.Q., Bradley, I.V., Wells, J-P.R., Gregorkiewicz, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01-12-2001; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Elemental semiconductors and insulators; Energy transfer; Exact sciences and technology; Free-electron laser; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Photoluminescence; Physics; Rare-earth ions; Semiconductors; Semiconductors; Free-electron laser; Rare-earth ions; Energy transfer; Photoluminescence; Elemental semiconductors; Optical properties; Transition element additions; Doped materials; Rare earth additions; Shallow impurities; Silicon; Experimental study; III-V semiconductors
• ISSN: 0022-2313; 1872-7883
• DOI: 10.1016/S0022-2313(01)00287-3

Shallow levels determine electrical and optical properties of semiconductors. Mid-infrared radiation from a free-electron laser can be used for an effective ionization of shallow impurities, leading to a variety of effects. In contrast to thermal ionization, the optically induced ionization process can be tuned to a particular level by adjusting the wavelength. In this way, different impurity and defect levels can be selectively addressed. The short-pulsed output of the free-electron laser allows the experiments to be performed in a manner, which utilizes its unique characteristics.
In this contribution, we show how two-color spectroscopy with a free-electron laser can be used to unravel energy transfer between different centers in semiconductor matrices. In particular, energy storage at shallow centers in silicon and mid-infrared-induced Auger recombination process of long-living optically active centers will be discussed. Specific examples for rare earth- and transition metal-doped silicon and rare earth-doped III–V semiconductors will be presented.