AlGaAs/GaAs Laser Diodes with GaAs Islands Active Regions on Si Grown by Droplet Epitaxy

The AlGaAs/GaAs laser diodes with the self-formed GaAs islands active regions on the Si substrates, showed a threshold current ( I th ) of 260 mA, a threshold current density ( J th ) of 5.4 kA/cm 2 and a lasing wavelength of 791 nm with the full width at half-maximum (FWHM) of 2.8 nm under pulsed condition at 300 K and an I th of 110 mA, a J th of 3.9 kA/cm 2 and a lasing wavelength of 771 nm with the FWHM of 1.8 nm under a continuous-wave condition at 100 K. The self-formed GaAs islands on Si, grown by the droplet epitaxy, exhibited a conical shape with heights of 8 nm and effective diameters of 300 nm. Compared with the conventional quantum well laser diode on Si, the self-formed laser diode on Si exhibited an improved reliability due to the reduction of the dislocation number in the active region.