RGB monolithic GaInN-based μLED arrays connected via tunnel junctions

Abstract

We report a 330 ppi monolithic RGB micro light-emitting diodes (μLED) array of blue, green and red GaInN-based LEDs stacked on the same wafer. Considering it is challenging to form ohmic electrodes on the plasma-etched p-type GaN surface, GaInN-based tunnel junctions were used to connect each LED, and anode electrodes for the blue and green LEDs were formed on n-type AlGaN. The fabricated stacked monolithic μLED arrays were tested at room temperature (approximately 26 °C) and DC. Each μLED emitted blue, green and red with peak wavelengths of 486, 514 and 604 nm at a current density of 50 A cm−2.