Optical properties of InAs quantum dots grown on patterned Si with a thin GaAs buffer layer.

InAs quantum dots (QDs) were grown on patterned Si substrates with a thin GaAs buffer using SiO2 as a mask by molecular beam epitaxy. GaAs was firstly selectively grown on the exposed Si surface with feature size around 250 nm. The InAs QDs were selectively grown on top of the GaAs. Low temperature photoluminescence (PL) measurements show strong optical activity in the wavelength range from 900 to 1050 nm. The temperature dependent measurement of the PL response indicates that, for temperatures over 110 K, the carrier escape from quantum dots leads to quenching of the signal. The PL results demonstrate that using nanostructures, it is possible to integrate high quality direct gap III-V materials on Si with high optical activity, leading to potentially new optoelectronic applications on Si and other convenient substrates which are lattice mismatched to InAs and other III-V materials. [ABSTRACT FROM AUTHOR]