This invention relates to relates to silicon light emitting devices (SiLEDs), and its application into current Complementary Metal Oxide Semiconductor (CMOS) technology, as well into future Silicon on Insulator (SOI) technology. According to the invention, a silicon based light emitting device is designed to operate by means of avalanche carrier multiplication and emitting at the below threshold wavelength detection range for Silicon of 850nm and such that it is compatible with CMOS silicon nitride, silicon oxi-nitride and polymer waveguide technology. This favours diverse electro-optical system applications such as electro-optical couplers, fast data transfer on and from chip, various optical interconnect configurations as well as diverse on-chip sensor, fluidic and micro-optical-mechanical sensor applications.; Under particular operating conditions emissions at specific wavelengths (for example the longer wavelengths) may be favoured, while in other cases tuning of the emitted radiation may be obtained.