PHOTOLUMINESCENCE AND ELECTROLUMINESCENCE CHARACTERIZATION OF ERBIUM-DOPED SIGE

We have performed photo- and electroluminescence measurements on erbiu m doped silicon and SiGe samples containing different amounts of germa nium. All samples were grown completely by molecular beam epitaxy. Oxy gen was used as a codopant to enhance the luminescence efficiency. The photoluminescence data show a systematic variation of the thermal act ivation energy obtained from temperature dependent intensity measureme nts with varying germanium contents. For samples with an alternating S i/SiGe layer structure stronger photoluminescence is observed when the erbium ions are incorporated into the SiGe layers rather than into th e silicon layers. We attribute this to the capture of photogenerated c arriers in the SiGe layers. Electroluminescence from erbium doped SiGe samples which have been processed as diodes has been observed up to r oom temperature in both surface and edge emitting geometries. (C) 1998 American Vacuum Society.