Parallel-Unit Count and Temperature-Dependent Optoelectronic Performance of Green Micro-LEDs

Abstract

Thermal management is critical for high-resolution micro light-emitting diode (micro-LED) displays, as elevated junction temperatures compromise luminous efficiency and device reliability. This article investigates the optoelectronic performance of green InGaN/GaN micro-LED arrays with varying parallel-unit counts. While increasing the number of parallel units enhances optical output, it exacerbates heat accumulation. In particular, increasing the unit count from 1 to 4 reduces the peak external quantum efficiency (EQE) from 17.39% to 14.24% and shifts the corresponding current density ( ${J}_{\text {EQE},\textit {max}}\text {)}$ from 5.98 to 6.31 A/cm2. These thermal degradation effects are intensified when the operating temperature rises from 293 to 333 K, evidenced by a continuous EQE drop, a higher ${J}_{\text {EQE},\textit {max}}$ , and spectral broadening. The study demonstrates a synergistic amplification between ambient heat and the additional thermal load from array integration, emphasizing the critical need for efficient thermal design in high-brightness, integrated micro-LED arrays.