Weak polarization electric field Ⅲ-N LEDs on polar plane with enhanced efficiency and strong lateral carrier confinement

Weak polarization electric field (PEF) III-nitride LEDs provide a promising pathway toward high-performance micro-LEDs for next-generation displays and wearable devices. To realize this promise, improving the efficiency of weak-PEF LEDs is crucial, as it remains the central requirement for next-generation optoelectronic applications. Here, we demonstrate record-high efficiency weak-PEF LEDs on polar c-plane with InGaN/AlGaN digital alloy (DA) superlattice barriers, enabled by optimized pulse-growth mode of metal-organic chemical vapor deposition (MOCVD). In addition, we reveal strong lateral carrier confinement in these LEDs. We improve the structural quality and optical performance of weak-PEF InGaN/DA multiple quantum wells (MQWs) by optimizing the pulse-growth conditions. Further, we realize weak-PEF DA-based blue LEDs with peak external quantum efficiency up to 15%, which is the highest value in current studies of its kind. Importantly, weak-PEF DA-based LEDs have strong lateral carrier confinement, leading to less efficiency degradation from sidewall effects than conventional GaN-based MQWs LEDs. This work represents a meaningful step toward high-performance weak-PEF III-nitride LEDs, particularly for micro-LED applications where both efficiency and carrier confinement are critical.