Realization of 256--278 nm AlGaN-Based Deep-Ultraviolet Light-Emitting Diodes on Si Substrates Using Epitaxial Lateral Overgrowth AlN Templates

We demonstrated 256--278 nm AlGaN-based deep-ultraviolet (DUV) light-emitting diodes (LEDs) on Si substrates by using epitaxial lateral overgrowth (ELO) AlN templates. A 4-μm-thick ELO-AlN layer grown in a striped pattern along the $\langle 10\bar{1}0\rangle$ direction can be coalesced successfully. Low-threading-dislocation-density AlN templates were achieved on Si wafers by a combination of the ELO and NH 3 pulsed-flow multilayer growth methods. Single-peaked AlGaN LEDs with wavelengths shorter than 280 nm were achieved by fabricating them on ELO-AlN templates on Si. These low-cost AlGaN-based DUV LEDs on Si substrates are expected to be integrated on the same chips with Si-based electrical circuits.