Enhanced Light Output Power and Growth Mechanism of GaN-Based Light-Emitting Diodes Grown on Cone-Shaped SiO₂ Patterned Template

In this study, we successfully transferred the patterns of a cone-shaped patterned sapphire substrate (CPSS) intoSiO₂layer to fabricate a cone-shapedSiO₂patterned template by using nanoimprint lithography (NIL). The GaN-based light-emitting diodes (LEDs) were grown on this template by metal-organic chemical vapor deposition (MOCVD). The transmission electron microscopy (TEM) images suggest that the stacking faults formed near the cone-shapedSiO₂patterns during the epitaxial lateral overgrowth (ELOG) can effectively suppress the threading dislocations, which results in an enhancement of internal quantum efficiency. The Monte Carlo ray-tracing simulation reveals that the light extraction efficiency of the LED grown on cone-shapedSiO₂patterned template can be enhanced as compared with the LED grown on CPSS. As a result, the light output power of the LED grown on cone-shapedSiO₂patterned template outperformed the LED grown on CPSS.