InGaN Multiple Quantum Well Blue LED Grown on Patterned Sapphire Substrates

We reported the InGaN/GaN multiple quantum well (MQW) blue light-emitting diodes (LED) grown on patterned sapphire substrates (PSS). The surface morphologies for samples grown on the "dome" PSS in different growth stages were observed by scanning electron microscopy (SEM). The fully coalescence of the growth fronts was achieved for 30 minute growth sample with the "bumps" surface defects. We also used transmission electron microscopy (TEM) to analyze the LED layer structures grown on "dome" PSS. For lxl mm bare power chip measured with prober testing, the typical output power is up 345 mW at 350 mA current injection. The extraction efficiency of blue LED chip is enhanced at least by 25%, compared to those on c-planar sapphire. After white LEDs were simply packaged using blue LED chips and phosphor, the achievable better luminous flux was close to 98 lm for white LEDs grown on dome PSS. The effect of pattern sizes on the LED output power will be also discussed.