Green Island, NY, USA-based Crystal IS Inc, which makes ultraviolet light-emitting diodes (UVC LEDs) grown pseudomorphically (strained) on aluminum nitride (AlN) substrates, has achieved more than 65mW in optical output at 260nm from a single UVC LED operated in continuous-wave (cw) mode (Appl. Phys. Express 6 (2013) 032101).

“By employing die thinning and encapsulation techniques, we were able to increase the photon extraction efficiency to over 15%,” says founder & chief technology officer Leo Schowalter. Furthermore, improved thermal management and a high characteristic temperature resulted in low thermal roll-off up to 300mA injection current with output power of 67mW, an external quantum efficiency (EQE) of 4.9%, and a wall plug efficiency (WPE) of 2.5% for a single-chip UVC LED emitting at 271nm. “By fabricating our LEDs on our home-grown aluminium nitride substrates, we continue to set the pace of what is possible for the combination of highest efficiencies and longest lifetimes in the 250–280nm wavelength range, far surpassing diodes fabricated on sapphire,” Schowalter adds.

“This R&D accomplishment represents a more than six-fold increase in performance from just one year ago,” says CEO Larry Felton. “Our progress in business operations continues on a like pace, readying us and our LEDs for commercial success.”