Self-textured oxide structure for improved performance of 365 nm ultraviolet vertical-type light-emitting diodes

High performance 365 nm vertical-type ultraviolet light-emitting diodes (LEDs) are demonstrated by the insertion of a self-textured oxide mask (STOM) structure using metal-organic chemical vapor deposition. The dislocation densities were reduced significantly via the STOM by the observation of the transmission electron microcopy image. Under an injection current of 20 mA, a 50% light output power enhancement was achieved, representing an enhancement of 35.4% in light extraction efficiency and injected electron efficiency of the LED with STOM in comparison to that without STOM. At 350 mA, the light output power of the STOM-LEDs was approximately 24.4% higher. Measurements of the optical and electrical properties of the LED showed that the corrugated STOM structure improved the light scattering and reflection which increased the light output, and also enhanced the current spreading to intensify radiative recombination.