InP self assembled quantum dot lasers grown on GaAs substrates by metalorganic chemical vapor deposition

Abstract

We describe the operation of lasers having active regions composed of InP self-assembled quantum dots embedded in In0.5Al_0.3Ga_0.2P grown on GaAs (100) substrates by MOCVD. InP quantum dots grown on In_0.5Al_0.3Ga_0.2P have a high density on the order of about 1-2x10 cm^-2 with a dominant size of about 10-15 nm for 7.5 ML growth.[1] These In0.5Al_0.3Ga_0.2P/InP quantum dots have previously been characterized by atomic-force microscopy, high-resolution transmission electron microscopy, and photoluminescence.[2] We report here the 300K operation of optically pumped red-emitting quantum dots using both double quantum-dot active regions and quantum-dot coupled with InGaP quantum-well active regions. Optically and electrically pumped 300K lasers have been obtained using this active region design; these lasers show improved operation compared to the lasers having QD-based active regions with threshold current densities as low as Jth ~ 0.5 KA/cm².