Simulation of GaN-Based Light Emitting Diodes Incorporating Composition Fluctuation Effects

TL;DR

This paper presents a simulation approach that accurately predicts GaN-based LED performance by incorporating composition fluctuations within quantum wells, addressing limitations of traditional models.

Contribution

It introduces a novel simulation method that accounts for composition fluctuations in quantum wells, improving prediction accuracy for GaN/InGaN LED characteristics.

Findings

Incorporating composition fluctuations improves prediction accuracy.

The model explains transport mechanisms better than previous models.

Enhanced understanding of quantum well effects on LED performance.

Abstract

III-Nitride light emitting diodes (LEDs) are widely used in a range of high efficiency lighting and display applications, which have enabled significant energy savings in the last decade. Despite the wide application of GaN LEDs, transport mechanisms across InGaN/GaN heterostructures in these devices are not well-explained. Fixed polarization sheet charges at InGaN/GaN interfaces lead to large interface dipole charges, which create large potential barriers to overcome. One-dimensional models for transport across such heterostructures predict turn-on voltages that are significantly higher than that found in real devices. As a result, conventional models for transport cannot predict the performance of new designs such as for longer wavelength LEDs, or for multi-quantum well LEDs. In this work, we show that incorporating low and high Indium compositions within quantum wells at the submicron scale can provide accurate prediction of the characteristics of GaN/InGaN light emitting diodes.