Performance and Reliability of State-of-the-art Commercial UVC Light Emitting Diodes

Commercially-available, sapphire- and AlN-based ultraviolet-C light emitting diodes (UVC LEDs) emitting in the range of 265-275 nm were evaluated and compared. Both AlN- and sapphire-based devices produced clean emission lines without parasitics and well-exceeded the industry-required L70 lifetimes of 10,000 h. Electrical and optical characterization revealed that devices grown on native aluminum nitride (AlN) substrates sustained up to 2.6 times greater current density and 6 times higher output power densities than their counterparts grown on sapphire substrate. Interestingly, the cost-performance ($/mW) was similar for both platforms despite the significantly pricier AlN substrates.