Growth and characterizations of InP self-assembled quantum dots embedded in InAIP grown on GaAs substrates

We report the characteristics of InP self-assembled quantum dots embedded i n In0.5Al0.5P on GaAs substrates grown by metalorganic chemical vapor depos ition. The InP quantum dots show increased average dot sizes and decreased dot densities, as the growth temperature increases from 475 degreesC to 600 degreesC with constant growth time. Above the growth temperature of 600 de greesC, however, dramatically smaller and densely distributed self-assemble d InP quantum dots are formed. The small InP quantum dots grown at 650 degr eesC are dislocation-free "coherent" regions with an average size of simila r to 20 nm (height) and a density of similar to1.5 x 10(8) mm(-2). These In P quantum dots have a broad range of luminescence corresponding to red or o range in the visible spectrum.