Rare Earth Doped Semiconductors, Symposium Held in San Francisco, California on April 13-15, 1993. Materials Research Society Symposium Proceedings, Volume 301

Abstract : The properties of rare earth ions in solids have been studied in detail for decades, but until recently this work was restricted to dominantly ionic hosts such as fluorides and oxides, and to a lesser extent to more covalently bonded hosts, such as tetrahedral II-VI semiconductors. The idea of rare earth elements incorporated into covalent semiconductors such as GaAs and Si may be traced to a short communication in 1963 by R.L. Bell (J. Appl. Phys. 34, 1563 (1963)) proposing a dc-pumped rare earth laser. At about the same time, three unpublished technical reports appeared as a result of U.S. Department of Defense sponsored research in rare earth doped Si, GaAs, and InP to fabricate LEDs. Attempts by Lasher et al., Betz et al., and Richman et al. to identify sharp 4f specific emissions in these hosts essentially failed