Open AccessImprovement of the light extraction efficiency of GaN-based LEDs using rolled-up nanotube arrays
Author(s) -
Mehrdad Djavid,
X. Liu,
Zetian Mi
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.0a1680
Subject(s) - light emitting diode , materials science , optoelectronics , nanotube , extraction (chemistry) , diode , optics , carbon nanotube , nanotechnology , physics , chemistry , chromatography
In this paper, we have investigated the effect of rolled-up nanotubes on the light extraction efficiency of GaN-based LEDs using two-dimensional finite element method simulation. The light extraction involves two successive steps, including the coupling from the light source to the tube and the subsequent emission from the tube to the air. Significantly enhanced light extraction efficiency is observed for both TE and TM waves by optimizing the nanotube geometry and dimension as well as the separation between the nanotube and light source. We have further shown that densely packed nanotube arrays can be integrated with GaN-based LEDs to achieve unequivocal improvement of light extraction efficiency over a large surface area. With recent advances in rolled-up micro- and nanotubes, it is expected that this study can offer a potentially flexible, low cost approach to enhance the light extraction of various LED devices.