Output power enhancement of GaN-based flip-chip light-emitting diodes via conical structures generated by a monolayer of nanospheres

This letter describes the output power enhancement of the GaN-based flip-chip light-emitting diodes (FC LED) featuring conical structures fabricated by etching a self-assembled monolayer SiO2 spheres as the hard mask. By roughening the surface of FC LED components, it increases structural size of the components and elevates the light extraction efficiency of FC LED. At a constant current of 400 mA, the output power of the FC LED with 1200 nm conical structures is 638.1 mW and enhanced by 6.1% compared with the FC LED without surface roughening