Self-assembled InP quantum dots for red LEDs on Si and injection lasers on GaAs

Abstract

Red-light-emitting LED structures and injection lasers have been prepared by solid source molecular beam epitaxy. The LED structures were grown on Si substrate and consist of a low-temperature GaAs buffer layer and a single layer of self-assembled InP quantum dots embedded in Ga 0.51In 0.49P matrix. The LED structure shows intense InP dot-related photoluminescence at 1.77 eV at 8 K. Separate confinement heterostructure lasers were grown on GaAs (1 0 0). They contain densely stacked layers of self-assembled InP quantum dots embedded in Ga 0.51In 0.49P waveguide and Si/Be doped Al 0.53In 0.47P cladding layers. The edge emitting laser diodes show quantum dot lasing in the visible part of the spectrum (690–705 nm) at temperatures up to −30°C with a low threshold current density of 172 A/cm 2 at 90 K increasing with temperature up to 685 A/cm 2 at 210 K.