Individually-addressable flip-chip AlInGaN micropixelated light emitting diode arrays with high continuous and nanosecond output power

Micropixelated blue (470nm) and ultraviolet (370nm) AlInGaN light emitting diode (‘micro-LED’) arrays have been fabricated in flip-chip format with different pixel diameters (72µm and 30µm at, respectively, 100 and 278 pixels/mm2). Each micro-LED pixel can be individually-addressed and the devices possess a specially designed n-common contact incorporated to ensure uniform current injection and consequently uniform light emission across the array. The flip-chip micro-LEDs show, per pixel, high continuous output intensity of up to 0.55µW/µm2 (55W/cm2) at an injection current density of 10kA/cm2 and can sustain continuous injection current densities of up to 12kA/cm2 before breakdown. We also demonstrate that nanosecond pulsed output operation of these devices with per pixel on-axis average peak intensity up to 2.9µW/µm2 (corresponding to energy of 45pJ per 22ns optical pulse) can be achieved. We investigate the pertinent performance characteristics of these arrays for micro-projection applications, including the prospect of integrated optical pumping of organic semiconductor lasers.