Luminous characteristics of high-voltage blue mini-light-emitting diodes

The luminous characteristics of flip-chip type high-voltage (HV) blue mini-light-emitting diodes (LEDs), which consist of three serially connected sub-mesas, have been investigated for the first time. The cryogenic electroluminescence below 100 K partially originates from localized excitons. As the driving current reaches 1 μA, the contributions of Shockley–Read–Hall nonradiative recombination and radiative recombination exhibit a remarkably inverse temperature dependence, while the contributions of Auger recombination and carrier leakage are relatively negligible. The mesa corresponding to the anode of the HV blue mini-LED exhibits the lowest temperature among the three sub-mesas due to its smaller thermal resistance. To minimize the temperature-induced shift in chromaticity coordinates, it is necessary to adjust the driving current based on the operating temperature.