Properties of erbium luminescence in bulk crystals of silicon carbide

The infrared luminescence of Er3+ ions has been studied in bulk crystals of silicon carbide 6H-SiC doped with erbium in the process of their growth. T he erbium centers of different symmetry in the crystals are revealed by the EPR technique. A number of intense luminescence bands of erbium ions are o bserved at a wavelength of about 1.54 mu m. The luminescence can be excited by the light with quantum energies above and below the band gap of SiC. It is found that the luminescence exhibits unusual temperature behavior: as t he temperature increases, the luminescence intensity abruptly rises startin g with 77 K, passes through a maximum at similar to 240 K, and, in the vici nity of similar to 400 K, decreases down to the values observed at 77 K. Th e activation energies for the flare-up and quenching of the Er3+ luminescen ce are estimated at E-A approximate to 130 and approximate to 350 meV, resp ectively. The mechanisms of the flare-up and quenching of the Er3+ luminesc ence in SiC are discussed. (C) 2000 MAIK "Nauka/Interperiodica".