The mechanism in efficient silicon light-emitting diodes


The mechanism in efficient silicon light-emitting diodes

Sun, J. M.; Dekorsy, T.; Skorupa, W.; Schmidt, B.; Mücklich, A.; Helm, M.

Light emission from silicon is one of the hot topics of temporary semiconductor physics and technology. Recent papers report encouraging electroluminescence efficiencies observed from bulk silicon diodes prepared by boron implantation. This report deals with a detailed analysis of the mechanism in light emission from silicon pn diodes prepared by boron implantation. From low-temperature electroluminescence spectra in combination with structural analysis, we obtain evidence that the light emission is strongly related to the locally enhanced boron doping spikes produced by ion implantation and subsequent annealing, which act as potential minima for holes and barriers for electrons. The doping spikes are able to capture spatially indirect bound excitons with a low recombination rate, thus effectively suppressing the fast non-radiative recombination at defects. The captured indirect bound excitons are thermally released to free electron-hole pairs at elevated temperature; therefore contribute to an increase of the band edge electroluminescence. A model containing rate equations of bound excitons and free excitons gives a very well description on the anomalous temperature dependence, which was observed in the efficient silicon light emitting diodes.

Keywords: Electroluminescence; silicon pn diode; bound excitons

  • Contribution to proceedings
    Vth International Conference, Ion Implantation and Other Applications of Ions and Electrons, 14.-17.06.2004, Kazimierz Dolny, Poland

Permalink: https://www.hzdr.de/publications/Publ-6640
Publ.-Id: 6640