Transition and rare-earth elements in the SiC and GaN wide-gap semiconductors: recent EPR studies

EPR studies of transition-element ions in SiC and GaN and of erbium in 6H-S iC are reported. Data are presented on Sc2+ ions and scandium acceptors, an d chromium and molybdenum ions in various charge states in SiC. A study was made of nickel and manganese in nominally pure GaN grown by the sandwich s ublimation method. The first EPR investigation of Er in 6H-SiC is reported. Erbium was identified from the hfs of the EPR spectra. Various possible mo dels of erbium centers in silicon carbides are discussed. Strong room-tempe rature erbium-ion luminescence was observed. (C) 1999 American Institute of Physics. [S1063-7834(99)02705-7].