Analysis of Carrier Accumulation in Active Region by Energy Loss Mechanisms in InGaN Light-Emitting Diodes

TL;DR

This paper investigates carrier transport and recombination in InGaN/GaN LEDs, revealing that carrier accumulation and spill-over significantly influence efficiency droop and forward voltage as injection current varies.

Contribution

It introduces a new perspective by separately analyzing carrier energy loss to explain carrier accumulation and spill-over effects in InGaN LEDs.

Findings

Carrier accumulation leads to efficiency droop.

Carrier spill-over affects forward voltage.

Energy loss analysis clarifies carrier dynamics.

Abstract

Carrier recombination and transport processes play key roles in determining the optoelectronic performances such as the efficiency droop and forward voltage in InGaN/GaN multiple-quantum-well (MQW) light-emitting diodes (LEDs). In this work, we investigate the dominant carrier transport and recombination processes inside and outside the MQW region as a function of injection current from a new point of view by separately examining the carrier energy loss. Analysis of the measurement results reveals that the carrier accumulation and subsequent spill-over from the MQW active region to the clad is the most probable mechanism of explaining the efficiency and forward voltage variation with the injection current.