Near-field radiation and the effect of non-uniformity of current density distribution in AlInGaN micro-leds

The object of study in this work was the rapidly developing micro-LEDs based on AlGaInN nanoheterostructures, which have high electroluminescent characteristics and open up new application possibilities. A study of near-field radiation with high spatial resolution (mapping) revealed high current density inhomogeneity over a wide range of excitation levels, namely, the concentration of light and current in the annular region adjacent to the side surface of the mesa. Taking this effect into account, the concept of “effective” current density is introduced, and the current dependences of energy characteristics are analyzed, including optical power saturation and efficiency droop.