Two-step lateral growth of GaN for improved emission from blue light-emitting diodes

•A two-step growth approach and the application of silica-nanospheres were established.•The structural and optical properties were studied.•Dislocations were effectively blocked by silica-nanospheres.•A 2.7 times enhancement EL emission from silica-nanosphere embedding light-emitting diodes is ascribed.•The crystal quality of GaN and light extraction efficiency were improved.

A two-step growth approach based on facet-controlled epitaxial lateral growth and the application of silica nanospheres was established to enhance the performance of GaN based light-emitting diodes (LEDs). In the first step, open inverted honeycomb cones (IHCs) were fabricated. These IHCs were filled with silica nanospheres and a second growth step was performed. As compared to LEDs fabricated on IHC templates, 2.7 fold electroluminescence (EL) intensity was obtained for silica nanospheres-stacked IHC due to improved crystal quality and light scattering at silica nanospheres. Simulation of emission intensity was carried out to determine the effect of dislocation density reduction on EL enhancement of the LEDs.