A silicon light emitter in telecom-band based on a single germanium quantum dot precisely embedded in a silicon photonic crystal nanocavity is fabricated by a scalable method. A sharp resonant luminescence peak is observed at 1498.8 nm, which is enhanced by more than three orders of magnitude. The Purcell factor for the fundamental resonant mode is estimated from enhancement factor and increased collection efficiency. The cavity modes coupled to the ground state and excited state emission of germanium quantum dot are identified in the luminescence spectrum. Our devices provide a CMOS-compatible way of developing silicon-based low-power consuming light emitters, and are promising for realizing on-chip single photon sources.

Self-assembled GeSi nanostructures on periodic Si (001) sub-micro pillars (SMPs) are systematically studied. Different GeSi nanostructures, including circularly arranged quantum dots, quantum rings and quantum dot molecules can be readily obtained at the edge of the pillars by controlling the growth temperatures and the diameter of the pillar. These phenomena are explained by taking into account the surface chemical potential around the top terrace of SMPs, which is considerably affected by the formation of {113} facets. Our results demonstrate a feasible route to obtain novel periodic Si pillars embedded with the desired GeSi nanostructures, which have promising applications in optoelectronic devices.

The peculiar properties of the gapless surface states with a Dirac cone shaped energy dispersion in topological insulators (TIs) enable promising applications in photodetection with an ultra-broad band and polarization sensitivity. Since many TIs can be easily grown on silicon (Si) substrates, TIs on Si could make an alternative route for photon detection of Si photonics. We present good device performances of a Si-based single-crystal bismuth telluride (Bi 2 Te 3) photoconductive detector. Room temperature photo responses to 1064 nm and 1550 nm light illumination were demonstrated. Linear dependences of the photocurrent on both the incident light power and the bias voltage were observed. The main device parameters including responsivity and quantum efficiency were extracted.

No abstract