(Invited) Enhanced Efficiency of AlInN Nanowire Ultraviolet Light-Emitting Diodes Using Photonic Crystal Structures

Abstract

In this paper, we report on the enhanced light extraction efficiency (LEE) of AlInN nanowire ultraviolet light-emitting diodes (LEDs) at an emission wavelength of 283 nm using the surface passivation approach and hexagonal photonic crystal structures. Several dielectric materials including SiO2, Si3N4, HfO2, AlN, and BN, have been investigated as the surface passivation layer for the AlInN nanowire LEDs. The LEDs using these dielectric materials show significantly improved LEE compared to that of the unpassivated ultraviolet nanowire LEDs. With a 35nm Si3N4 as surface passivation, the AlInN LED could achieve a LEE of ~ 42.6%, while the unpassivated LED could only have an average LEE of ~ 25.2%. Moreover, the LEE of the AlInN nanowire LEDs could be further increased using hexagonal photonic crystal structures. The periodically arranged nanowire LED arrays could reach up to 63.4% which is almost two times higher compared to that of the random nanowire LEDs. Additionally, the AlInN nanowire ultraviolet LEDs exhibit highly transverse-magnetic polarized emission.