Optimizing light extraction efficiency in inclined sidewall type ultraviolet light-emitting diodes with nanopatterned sapphire substrates and photonic crystals.

Herein, we focus on the performance optimization of inclined sidewall (IS) type ultraviolet (UV) light-emitting diodes (LEDs) with either nanopatterned sapphire substrates (NPSSs) or photonic crystals (PCs). The simulation results demonstrate the introduction of substrate patterning plays a crucial role in unlocking the potential of IS type UV LEDs by reducing the generation of high mode resonance within the device. The use of NPSSs design performs exceptionally well in extracting transverse-magnetic (TM) polarized light due to its superior alignment with the inclination design. As a result, the total light extraction efficiencies (LEEs) are significantly improved, increasing from 36.0 to 57.3%. [ABSTRACT FROM AUTHOR]