Size-independent peak external quantum efficiency (>2%) of InGaN red micro-light-emitting diodes with an emission wavelength over 600 nm

Red micro-light-emitting diodes (μLEDs) have been generated significant interest for the next generation μLEDs displays. It has been shown that the external quantum efficiency (EQE) of AlInGaP red μLEDs markedly decreases as the size goes to very small dimension. Here, we demonstrate size-independent peak EQE of 611 nm InGaN red μLEDs. Packaged μLEDs show a peak EQE varied from 2.4% to 2.6% as the device area reduces from 100 × 100 to 20 × 20 μm2. These results demonstrate the promising potential for realizing high efficiency red μLED with very small size using InGaN materials.