606-nm InGaN amber micro-light-emitting diodes with an on-wafer external quantum efficiency of 0.56%

We demonstrated amber InGaN 47 × 47 μ2 micro-light-emitting diodes (μLEDs) with the peak wavelength of 606 nm and full-width at maximum (FWHM) of 50 nm at 20 A/cm2. The amber μLEDs exhibited a 33-nm blue-shift of the peak wavelength and obtain broader FWHMs to approximately 56 nm at 5 to 100 A/cm2. The peak on-wafer external quantum efficiency was 0.56% at 20 A/cm2. The characteristic temperature was 50.80 K at 20 to 60 A/cm2 but increased to 120.140 K at 80 to 100 A/cm2. The strong increase in the characteristic temperature from 60 to 80 A/cm2 could mainly be attributed to the saturation of the Shockley-Read-Hall non-radiative recombination at high current densities.