High-temperature electroluminescence properties of InGaN red 40 x 40 μm2 micro-light-emitting diodes with a peak external quantum efficiency of 3.2%

We study the high-temperature electroluminescence properties of 600 nm InGaN red 40 x 40 mu m(2) micro-light-emitting diodes (mu LEDs) with a peak external quantum efficiency (EQE) of 3.2%. Temperature-dependent peak wavelength measurements show a low redshift of 0.05 nm/K. The injection efficiency improves with increasing temperature. The hot/cold (HC) factor is used to quantify the thermal droop: at 400 K, the EQE and wall-plug efficiency HC factors at 50 A/cm(2) reach high values of 0.72 and 0.85, respectively. This demonstrates the robustness of InGaN red mu LEDs up to high temperature, with a much-improved stability over conventional AlInGaP red mu LEDs.