Investigation into the InAs/GaAs quantum dot material epitaxially grown on silicon for O band lasers

In As/Ga As quantum dot(QD) lasers were grown on silicon substrates using a thin Ge buffer and three-step growth method in the molecular beam epitaxy(MBE) system. In addition, strained superlattices were used to prevent threading dislocations from propagating to the active region of the laser. The as-grown material quality was characterized by the transmission electron microscope, scanning electron microscope, X-ray diffraction, atomic force microscope, and photoluminescence spectroscopy. The results show that a high-quality Ga As buffer with few dislocations was obtained by the growth scheme we developed. A broad-area edge-emitting laser was also fabricated. The O-band laser exhibited a threshold current density of 540 A/cm~2 at room temperature under continuous wave conditions. This work demonstrates the potential of large-scale and low-cost manufacturing of the O-band In As/Ga As quantum dot lasers on silicon substrates.