Demonstration of Multi-Active Region P-down Green LEDs with High Quantum Efficiency

TL;DR

This paper demonstrates high-efficiency green LEDs with multi-active regions and p-down topology, effectively addressing the green gap challenge by improving wall-plug efficiency at longer wavelengths.

Contribution

It introduces a novel multi-active region p-down LED design that achieves high external efficiency in the green spectrum, overcoming efficiency drops at high current densities.

Findings

High external efficiency in green LEDs achieved

Significant improvement in wall-plug efficiency

Effective voltage and EQE scaling demonstrated

Abstract

Longer wavelength emitters such as green LEDs display a pronounced efficiency drop at higher current densities, resulting in relatively low wall-plug efficiency. Multi-active region approach can improve the wall-plug efficiency significantly and tackle the green gap challenge. This work reports multi-active region p-down LEDs with high external efficiency operating entirely in the green wavelength. Devices were developed using p-down topology, where the PN junction is oriented such that electric fields from depletion and built-in polarization dipoles are aligned. Ga-polar multi-active region green LEDs with excellent voltage and EQE scaling, and significantly higher wall-plug efficiency is demonstrated in this work.