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GaN-based MQW light-emitting devices

The GaN-based MQW laser diodes have been improved excellently by introducing GaN/GaInN optical-guiding. The continuous wave laser operation at room temperature has been achieved at the wavelength of 410 nm. The lifetime of room temperature continuous wave operation is longer than 60 minutes at around 1 mW output. The external efficiencies of GaInN/GaN MQW blue and green light emitting diodes (LEDs) have been increased by newly developed flip-chip (FC) type LED lamp structure. The luminous intensities of the FC-type blue and green LEDs were typically 6 cd and 14 cd at 20 mA, respectively. The FC-type blue and green LEDs are the brightest levels in the world currently. The peak wavelengths and full widths at half maximums were typically 464 nm and 27 nm for the blue LEDs, and 515 nm and 32 nm for the green LEDs.

Room Temperature CW Operation of GaN-Based Blue Laser Diodes by GaInN/GaN Optical Guiding Layers

GaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm 2 ). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.

GaN-based multiple quantum well light-emitting devices

The GaN-based multiple quantum wells (MQW) laser diodes have been improved excellently by introducing GaN/GaInN optical- guiding layers and by reducing dislocation density. The lifetime of continuous wave operation has been improved to longer than 300 hours with 3 mW at the wavelength of 409 nm.