606-nm InGaN Amber Micro-Light-Emitting Diodes With an On-Wafer External Quantum Efficiency of 0.56%

We demonstrated amber InGaN
$47\times 47\,\,\mu \text{m}^{{2}}$
micro-light-emitting diodes (
$\mu $
LEDs) with the peak wavelength of 606 nm and full-width at maximum (FWHM) of 50 nm at 20 A/cm
²
. The amber
$\mu $
LEDs exhibited a 33-nm blue-shift of the peak wavelength and obtain broader FWHMs to approximately 56 nm at 5 to 100 A/cm
²
. The peak on-wafer external quantum efficiency was 0.56% at 20 A/cm
²
. The characteristic temperature was 50–80 K at 20 to 60 A/cm
²
but increased to 120–140 K at 80 to 100 A/cm
²
. The strong increase in the characteristic temperature from 60 to 80 A/cm
²
could mainly be attributed to the saturation of the Shockley-Read-Hall non-radiative recombination at high current densities.