1.54 mu m Light emission from Er/O and Er/F doped Si p-i-n diodes grown bymolecular beam epitaxy

Various light emitting devices (LED) have been processed using Er/O- and Er /F-doped Si layered structures grown by molecular beam epitaxy (MBE) at low temperature. A comparative study has been carried out in order to provide more understanding of the electroluminescence (EL) excitation and de-excita tion mechanisms in particular at a high injection current regime. Comparing the experimental results with model calculations the values of excitation cross section, sigma(ex), and effective Auger coefficient, C-A, have been d etermined for various devices operated at different biases. Time-resolved E L measurements of these Er/O- and Er/F-doped MBE Si structures, using an ex perimental set-up with a time response of 200 ns, have been performed with different excitation conditions. Besides the spontaneous Er emission ( simi lar to 700 mu s), some fast EL decay processes associated with the Anger en ergy transfer via free carriers (similar to 4 mu(s)), and the hot carrier e ffects (less than or similar to 200 ns) have been identified. (C) 1999 Else vier Science B.V. All rights reserved.