Electroluminescence at 1.54 μm in Si:Er/Si structures grown by sublimation molecular-beam epitaxy

In Si:Er/Si diode structures grown by sublimation molecular-beam epitaxy in a vacuum with a pressure of ～10^?7 mbar at temperatures 520–580°C, the intensity of room-temperature electroluminescence at 1.54 μm is studied as a function of the concentration and distribution of erbium and donor impurities in the space-charge region (SCR) and the SCR width. Methods for obtaining electroluminescence in diodes with a wide (0.1–1 μm) SCR are developed. The mean free path of electrons with respect to their interaction with Er centers and the threshold energy a free electron needs in order to excite an Er-shell electron are determined. The values of electric-field strength corresponding to breakdown in silicon p-i-n diodes with and without Er doping are obtained experimentally. A model describing the interaction of hot electrons with Er centers is suggested.