Visible electroluminescence (630 nm) from direct bandgap GaInP quantum dots grown on transparent GaP substrates

Not much progress has been made with optoelectronic devices on GaP and Si substrates owing to the lack of light emitting materials that can be epitaxially grown on these substrates with a low defect density. All currently available light emitting semiconductor compounds have lattice constants different from GaP and Si lattice constants, and therefore no thin films of useful thicknesses can be grown defect-free. Recently a new technique of embedding pockets of strained material into a host matrix without dislocating the crystal lattice has received much attention: strain-induced self-assembled quantum dots. Indeed, InAs/GaAs quantum dots have been successfully used as the active region of semiconductor laser devices with excellent device characteristics. We used a similar approach to induce formation of light-emitting GaInP quantum dots on GaP substrates. In this presentation, we report fabrication of light-emitting diodes (LEDs) with GalnP quantum dots as the active region.