Optical characterizations of GaN nanorods fabricated by natural lithography

We fabricated GaN/Sapphire nanorods by nanosphere lithography (NSL) using SiO2 nanospheres. Arrays of SiO2 nanospheres were packed on GaN, followed by dry-etching via inductively coupled plasma (ICP) etching. SiO2 nanospheres served as the etching mask under our etching conditions. Finally, a sapphire substrate under GaN was exposed by dry-etching. A significant blue shift was observed in the room temperature photoluminescence (PL) spectrum from GaN/Sapphire nanorods when the underlying Al2O3 was exposed. GaN nanorods were fabricated by simple and reproducible methods, where SiO2 nanospheres were successfully used as the etching mask. In addition, a blueshift in PL by the band-filling effect was observed due to the GaN nanostructures.