Effects of size on the electrical and optical properties of InGaN-based red light-emitting diodes

Zhe Zhuang,Daisuke Iida,Kazuhiro Ohkawa

doi:10.1117/12.2577244

Abstract

This work found larger red chips exhibited lower forward voltages due to their lower series resistance originated from the device area. Moreover, a larger chip resulted in a longer emission wavelength, narrower full-width at half maximum (FWHM), and higher EQE at high currents. These characteristics are beneficial for InGaN-based red LEDs. On the other hand, smaller chips had merits of a high characteristic temperature of 399K. This characteristic temperature is almost similar level with the world record in AlGaInP-based red LEDs, suggesting that InGaN-based red LEDs with small chip sizes are good candidates for temperature tolerant lighting applications.

Highlights

InGaN-based blue/green light-emitting diodes (LEDs) have become increasingly prevalent in illumination and display applications, such as interior/exterior lighting and display backlights.[1,2,3]. Their performance declines rapidly with the emission wavelength, especially in the red region.[4,5]. This decline is related to the content of In in InGaN quantum wells (QWs)
Much effort has been devoted to improving InGaN-based red LEDs with approaches including InGaN quantum dots,[8] a semipolar InGaN buffer layer,[9] lattice-matched InGaN/ScAlMgO4(0001) templates,[10] and InGaN/GaN nanowires.[11,12]
We systematically investigated the EL characteristics at different currents, including the peak wavelength, full-width at half-maximum (FWHM), external quantum efficiency (EQE), and integrated intensity

Summary

Introduction

InGaN-based blue/green light-emitting diodes (LEDs) have become increasingly prevalent in illumination and display applications, such as interior/exterior lighting and display backlights.[1,2,3]. This work examines the effect of size on device performance using different rectangular chips on the same InGaN-based red LED wafer.

Results

Conclusion