ERBIUM IN SI - ESTIMATION OF ENERGY-TRANSFER RATE AND TRAP DEPTH FROMTEMPERATURE-DEPENDENCE OF INTRA-4F-SHELL LUMINESCENCE

We investigated the temperature dependence of erbium (Er) 4f-shell lum inescence decay time and intensity in silicon based on a multiphonon-a ssisted energy transfer model, which has been verified for the Yb-dope d InP system and has already been successfully applied to various ran- earth doped III-V semiconductors. The temperature dependence of the de cay time of-Er 4f-shell luminescence was calculated using two fitting parameters: the depth of a trap level related to the 4f-shell luminesc ence and the energy transfer probability between the Er 4f shell and t he electronic state of the silicon host. For Si:Er codoped with oxygen and Si:Er codoped with nitrogen, the calculated temperature dependenc e was compared with the experimentally observed temperature dependence . A reasonably good fit was obtained between the calculated results an d the experimental results, suggesting that the Er 4f-shell luminescen ce is caused by the multiphonon-assisted energy transfer. The estimate d energy transfer probability for Si:Er,N is larger than that for Si:E r,O, suggesting a stronger interaction between the Er 4f-shell and the Si host in Si:Er,N than in Si:Er,O. (C) 1998 American Institute of Ph ysics.