Room temperature photonic crystal band-edge lasing from nanopillar array on GaN patterned by nanosphere lithography

An ordered GaN nanopillar array fabricated by nanosphere lithography exhibited room temperature photopumped lasing via the photonic crystal band-edge effect. With a monolayer of self-assembled nanospheres as hard mask, the ordered pattern was transferred to the sample to form nanopillars by inductively coupled plasma dry etch. Under pulsed optical excitation, room temperature lasing with a low lasing threshold of 30 mJ / cm 2 was achieved. The dominant lasing peak, centered at 415.6 nm, corresponds to a band-edge mode at the Γ -point of the band diagram. A Q factor in the range of 600-700, and spontaneous emission coupling factor of 0.021 were evaluated.