Erbium in Si: Estimation of energy transfer rate and trap depth from temperature dependence of intra-4f-shell luminescence

We investigated the temperature dependence of erbium (Er) 4f-shell luminescence decay time and intensity in silicon based on a multiphonon-assisted energy transfer model, which has been verified for the Yb-doped InP system and has already been successfully applied to various rare-earth doped III–V semiconductors. The temperature dependence of the decay time of Er 4f-shell luminescence was calculated using two fitting parameters: the depth of a trap level related to the 4f-shell luminescence and the energy transfer probability between the Er 4f shell and the electronic state of the silicon host. For Si:Er codoped with oxygen and Si:Er codoped with nitrogen, the calculated temperature dependence was compared with the experimentally observed temperature dependence. A reasonably good fit was obtained between the calculated results and the experimental results, suggesting that the Er 4f-shell luminescence is caused by the multiphonon-assisted energy transfer. The estimated energy transfer probability for Si:Er,N is larger than that for Si:Er,O, suggesting a stronger interaction between the Er 4f shell and the Si host in Si:Er,N than in Si:Er,O.