Role of codopants in the luminescent output from Si:Er

Abstract

A crystal-field model for the electronic structure of the Er3+ ion in silicon is presented. The parameters within the model are adjusted in order that the Stark energy splittings within the f shell reproduce the observed spectral features in a Si:Er sample that is codoped with nitrogen. The dominant crystal field possesses tetrahedral symmetry. Several additional spectral features are attributed to local mode vibrational sidebands. From this analysis, I conclude that the role of the codopants is to isolate the Er ion so that the relaxation energy does not go into the production of lattice phonons.