The influence of buffer layer growth conditions on the crystal quality and residual stress of GaN film grown on silicon carbide substrate is investigated.It is found that the Al GaN nucleation layer with high growth temperature can efficiently decrease the dislocation density and stress of the GaN film compared with Al N buffer layer.To increase the light extraction efficiency of GaN-based LEDs on Si C substrate,flip-chip structure and thin film flip-chip structure were designed and optimized.The fabricated blue LED had a maximum wall-plug efficiency of 72% at 80 m A.At 350 m A,the output power,the Vf,the dominant wavelength,and the wall-plug efficiency of the blue LED were 644 m W,2.95 V,460 nm,and 63%,respectively.
The influence of buffer layer growth conditions on the crystal quality and residual stress of GaN film grown on silicon carbide substrate is investigated. It is found that the A1GaN nucleation layer with high growth temperature can efficiently decrease the dislocation density and stress of the GaN film compared with A1N buffer layer. To increase the light extraction efficiency of GaN-based LEDs on SiC substrate, flip-chip structure and thin film flip-chip structure were designed and optimized. The fabricated blue LED had a maximum wall-plug efficiency of 72% at 80 mA. At 350 mA, the output power, the Vf, the dominant wavelength, and the wall-plug efficiency of the blue LED were 644 roW, 2.95 V, 460 nm, and 63%, respectively.