Photoluminescence of erbium-doped silicon: excitation power dependence

The intensity of the photoluminescence of erbium in silicon is analyzed by a model which takes into account the formation of free excitons, the bindin g of excitons to erbium ions, the excitation of inner-shell 4f electrons of erbium ions and their subsequent decay by light emission. Predictions of t his model for the dependence of luminescence intensity on laser excitation power are compared with experimental observations. The results for float-zo ne and Czochralski-grown silicon, in which erbium is introduced by implanta tion with or without oxygen co-implantation, are remarkably similar. To obt ain agreement between model analysis and experimental data it is necessary to include in the model terms describing energy dissipation by an Auger pro cess of both the erbium-bound excitons and the erbium ions in excited state with free electrons in the conduction band. A good quantitative agreement is achieved. (C) 1999 American Institute of Physics. [S1063-7826(99)00306-3 ].