AlGaN-based ultraviolet light-emitting diode on high-temperature annealed sputtered AlN template

We demonstrate 297.5-nm AlGaN-based ultraviolet (UV) light-emitting diodes (LEDs) grown on a high-temperature annealed (HTA) sputtered AlN template upon sapphire substrate. After HTA at 1600 degrees C, full width at half maximum values of (0002) and (10 (1) over bar2) planes of the 200-nm sputtered AlN template are significantly improved from 120.7 to 2794.0 arcsec to 82.4 and 352.6 arcsec, respectively, showing comparable threading dislocation densities with the 2-mu m AlN template grown by high-temperature metal organic chemical vapor deposition (MOCVD). Therefore, typical AlN template grown by MOCVD is not necessary in our study. A UV LED grown on this HTA sputtered AlN template reaches light output power of 9.83mW at 100 mA and external quantum efficiency of 2.77% at 30 mA. Our result indicates that the HTA sputtered AlN template is able to replace the commonly used high-temperature MOCVD AlN templates and thus decrease the growth complexity and cost of AlGaN-based UV LEDs. (c) 2019 Elsevier B.V. All rights reserved.