InAsP/AlGaInP/GaAs QD laser operating at ∼770 nm

We present a study of metalorganic vapour phase epitaxy of ternary InAsP quantum dots in AlGaInP/GaAs for application in laser diodes. The properties of InAsP QD laser structures were compared with reference samples containing binary InP QDs. Based on X-ray diffraction, the molar fraction of arsenic in InAsP QDs was estimated to be ~25%. Room temperature liquid contact electro-luminescence measurements revealed a long wavelength shift of the InAsP QD emission to ~775 nm as compared with the InP QD emission at 716 nm and an increased full width at half maximum of the spontaneous emission (71 meV vs 50 meV). As cleaved, 4 mm long and 50 µm wide InAsP QD lasers operated in a pulsed regime at room temperature at ~770 nm with a threshold current density of 155 A/cm and a maximum output optical power of at least 200 mW. The maximum operation temperature was at least 380 K.