Point and extended defects engineering as a key to advancing the technology of light-emitting diodes based on single-crystal Si and SiGe layers

A conception of defect engineering in the device technology is briefly reviewed. Examples of defect engineering in the technology of Si-based light-emitting diodes (LEDs) with the room temperature (RT) Er- and Ho-related luminescence as well as SiGe-based LEDs with the RT near-band-edge luminescence are discussed. Effect of a temperature enhancement of the rare-earth-related electroluminescence (EL) intensity in the LEDs fabricated on the (1 1 1)-oriented Si substrates was observed at avalanche and tunnelling breakdown in p–n junctions and its nature was revealed. The analysis of the experimental data shows that recombination involving excitons is the dominant mechanism of near-band-edge radiative recombination in all the Si1−xGex (0⩽x⩽1) light-emitting structures at RT. Some of them are characterized by record values of EL intensity and/or external quantum efficiency, so they can be used as effective light emitters for Si optoelectronics.