Abstract
Visible light-emitting diodes (LEDs) emitting at 619 nm and employing the InGaP/InGaAsP double heterostructure (DH) grown on a lattice-matched GaAs 0.61 P 0.39 substrate have been fabricated for the first time. The orange DH LEDs exhibit an external quantum efficiency of 0.22% and a full width at half maximum of 48 meV (15 nm) in the electroluminescence spectra.