Enhanced light output of GaN-based near-UV light-emitting diodes by using nanopatterned indium tin oxide electrodes

We report on the enhancement of the light output of near-UV (298 nm) GaN-based light-emitting diodes (LEDs) by using nanopatterned indium tin oxide (ITO) p-type contact layers. One-dimensional (1D) and two-dimensional (2D) nanopatterns are defined using a TiO₂ nano-mask, fabricated by means of a surface relief grating technique. The LEDs fabricated with the 1D and 2D nanopatterned p-type electrodes produce higher output powers by 33-48% (at 20 mA) as compared to those fabricated with the unpatterned contacts. The pattern-induced improvement of the output power is described in terms of the formation of the sidewalls of p-type electrodes.