Effect of resonant cavity in wafer-bonded green InGaN LED with dielectric and silver mirrors

The green InGaN-based resonant cavity light-emitting diodes (RCLEDs) on Si substrates were fabricated using laser liftoff and wafer bonding techniques. Five-pair TiO₂-SiO₂distributed Bragg reflectors (reflectivity: 85%) and an Ag metal layer (reflectivity: 99%) were employed as the top and bottom mirrors, respectively. The light output power of the RCLED at room temperature is 1.5 times the magnitude of a similar structure without a resonant cavity at an injecting current density of 600 A/cm². The mode spectrum exhibits a line width of approximately 5.5 nm at the dominant peak wavelength of 525 nm, which indicates a quality factor of 100. Under various injection current densities, a low thermally induced red shift in the 525-nm emission peak was observed. This indicates that the resonant microcavity effect contributes to the stability of electroluminescence emission wavelength.