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

We demonstrated amber InGaN 47×47 μm
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micro-light-emitting diodes ( μLEDs) with the peak wavelength of 606 nm and full-width at maximum (FWHM) of 50 nm at 20 A/cm
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. 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/cm
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. The peak on-wafer external quantum efficiency was 0.56% at 20 A/cm
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. The characteristic temperature was 50-80 K at 20 to 60 A/cm
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but increased to 120-140 K at 80 to 100 A/cm
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. The strong increase in the characteristic temperature from 60 to 80 A/cm
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could mainly be attributed to the saturation of the Shockley-Read-Hall non-radiative recombination at high current densities.