Efficiency droop in nitride‐based light‐emitting diodes

TLDR

Nitride-based LEDs exhibit a current-dependent drop in internal quantum efficiency, a phenomenon intensely studied worldwide yet lacking a universally accepted explanation. The article surveys current droop research, reviews proposed mechanisms, contextualizes them, and proposes a simple unified model for LED efficiency droop. The authors propose a simple yet unified model that captures the key factors contributing to LED efficiency droop. Illustration of LED efficiency droop is shown in Fig.

Abstract

Abstract Nitride‐based light‐emitting diodes (LEDs) suffer from a reduction (droop) of the internal quantum efficiency with increasing injection current. This droop phenomenon is currently the subject of intense research worldwide, as it delays general lighting applications of GaN‐based LEDs. Several explanations of the efficiency droop have been proposed in recent years, but none is widely accepted. This feature article provides a snapshot of the present state of droop research, reviews currently discussed droop mechanisms, contextualizes them, and proposes a simple yet unified model for the LED efficiency droop. magnified image Illustration of LED efficiency droop (details in Fig. 13 ).