Poster + Paper
14 March 2023 Demonstration of p-side down green light emitting diodes with high external quantum efficiencies
Sheikh Ifatur Rahman, Agnes Maneesha Dominic Xavier, Robert Armitage, Siddharth Rajan
Author Affiliations +
Conference Poster
Abstract
GaN/(In,Ga)N heterostructure based visible Light Emitting Diodes (LED) have enabled a wide range of solid-state lighting applications through excellent efficiency and power output in the shorter wavelengths (≤ 475nm) of violet/blue emission. However, the efficiency of emitters in the longer wavelength range (≥ 500nm) drops drastically due to the need to include higher Indium-content in the InGaN quantum wells. Large average polarization fields for high Indium-content quantum wells for conventional P-up structure, opposes the depletion field leading to large electrostatic barriers for both electrons and holes injection. LEDs fabricated along the N-polar direction with a p-up orientation or Ga-polar direction with p-down orientation lower such electrostatic barriers to carrier injection due to alignment of the polarization dipole field and depletion region field. This can therefore theoretically improve the electrical injection efficiency and reduce the forward voltage of operation. Such a Ga-polar p-down LED requires a bottom buried tunnel junction to avoid current spreading issues for a buried p-GaN layer. In this report, we demonstrate for the first time Ga-polar p-down green emitting LEDs using bottom tunnel junctions and having external quantum efficiencies comparable to those of equivalent p-up LEDs grown by Metal Organic Chemical Vapor Deposition (MOCVD).
© (2023) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Sheikh Ifatur Rahman, Agnes Maneesha Dominic Xavier, Robert Armitage, and Siddharth Rajan "Demonstration of p-side down green light emitting diodes with high external quantum efficiencies", Proc. SPIE 12441, Light-Emitting Devices, Materials, and Applications XXVII, 124410M (14 March 2023); https://doi.org/10.1117/12.2665221
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KEYWORDS
Light emitting diodes

External quantum efficiency

Quantum tunneling

Green light emitting diodes

Metalorganic chemical vapor deposition

Quantum wells

Gallium nitride

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