Over 20 MHz modulation bandwidth on 250 nm emission of AlGaN micro-LEDs

Abstract

Bandwidth measurements of deep ultra-violet micro-light-emitting diode (LED) electroluminescence centred at 250 nm using a multiple quantum well aluminium gallium nitride (AlGaN)-based LED structure grown on a sapphire substrate is presented. By controlled etching of the wafer surface, parabolically shaped micro-LED structures were formed to enhance light emission through the substrate. Devices were tested on-wafer and bandwidth measurements were carried out on individual emission peaks from the devices. A bandwidth of more than 20 MHz was achieved on the 250 nm peak.