Preparation and characterization of GaN photonic crystal arrays by focused ion beam technology

In this study, nano-patterned triangular photonic crystal arrays have been prepared on the surface of blue InGaN/GaN light-emitting diodes by focused ion beam technology. The nitride-based multilayer thin films were grown on c-plane (0001) sapphire substrates by low-pressure metal-organic chemical vapor deposition. The major emission peak wavelength was 468 nm. The nano-patterned array structures were implemented using a dual-beam nanotechnology workstation SMI 3050. The acceleration voltage of Ga ion beam was 30 kV, and the ion beam current was about 100 pA. The air-hole diameter in the triangular array has been 150 nm, while the periodicity ranged from 300 nm to 800 nm. The light–current measurements were carried out to reveal the light output intensity characteristics of the devices. In addition, the current–voltage study was shown with increased operation voltage from 3.0 V to 4.05 V while the period was decreased from 800 nm to 300 nm.

► Nano-patterning by focused Ga ion beam.
► Triangular photonic crystal arrays on InGaN/GaN light-emitting diodes.
► Thermal effects on electron–hole radiative recombination.
► Observed increased operation voltage with decreased period.