Self-assembled silicon-germanium nanostructures for CMOS compatible light emitters

To be commercially valuable, light emitters based on SiGe nanostructures should be efficient, fast, operational at room temperature, and be compatible with the CMOS technology. Also, the emission wavelength should match the optical waveguide low-loss spectral region of 1.3-1.6 μm. Among other approaches, epitaxially-grown Si/SiGe quantum dot/quantum well complexes produce efficient photoluminescence and electroluminescence in the required spectral range. Until recently, the major roadblocks for practical applications of these devices were strong thermal quenching of the luminescence quantum efficiency and a long carrier radiative lifetime. The latest progress in the understanding of physics of carrier recombination in Si/SiGe nanostructures is reviewed, and a new route toward CMOS compatible light emitters for on-chip optical interconnects is proposed.