Demonstration of 606nm-wavelength InGaN-based amber micro-LEDs toward red emission

We demonstrated amber InGaN-based micro LEDs (47 × 47 µm2) with 606 nm peak emission at 20 A/cm2. The amber LEDs were obtained the output power density of 2.26 mW/mm2 at 20 A/cm2 by on-wafer EL measurement. Also, the peak on-wafer EQE was obtained as 0.56%. The peak wavelength of the micro-LEDs exhibited a large blue-shift from 624 to 591 nm at 5 to 100 A/cm2. We evaluated the temperature stability of the micro-LEDs. It found that the characteristic temperature was gradually increased with current density increase because SRH non-radiative recombination could be suppressed at high current densities.