Efficient blue light emission from silicon - The first integrated Si-basedoptocoupler

We present the first all-silicon integrated optocoupler, whose fabrication, using ion implantation into SiO2, is completely compatible with standard S i technology. It is based on Ge-implanted SiO2 layers as light emitter exhi biting bright blue-violet electroluminescence light with a record wall-plug efficiency of 0.5%. The electroluminescence is explained with a model in w hich electrons enter the SiO2 layer via tunnel injection and excite the lum inescence centers by impact excitation or field ionization. A radiative T-1 -S-0 transition of these luminescence centers then causes the observed elec troluminescence. Finally, we show that these optocoupling devices hold grea t promise for integrated optoelectronic applications, especially in the fie ld of sensor and biotechnology. (C) 2001 The Electrochemical Society.