InP self-assembled quantum dots embedded inIn_0.5Al_0.3Ga_0.2P grown on GaAssubstrates by metalorganic chemical vapor deposition

摘要

We report the characteristics of InP self-assembled quantum dotsembedded in In_0.5Al_0.3Ga_0.2P on GaAssubstrates. InP quantum dots are grown at 650° C for variousdeposition times via the Stranski-Krastanow growth mode by metalorganicchemical vapor deposition. Atomic force microscopy and transmissionelectron microscopy show the formation of densely distributed coherentquantum dots. The InP quantum dots grown for up to“planar-layer-growth equivalent” 15 MLs have dominant sizesof 5-20 nm (height) and a density of ~10 dots/cm2. These InPquantum dots have broad range of luminescence corresponding to red ororange in the visible spectrum, depending on growth times. As thedeposition time increases, the photoluminescence peak shifts toward thelower energy side, due to an increase in the dominant size of thequantum dots. Also, optical pumping is performed on double-stacked InPquantum dot layers. In addition, InP/In_0.5Al_0.3Ga_0.2P/In_0.49Al_0.51P quantum dotheterostructures exhibit stimulated emission at room temperature andlaser operation at ~680 nm