Open AccessSize dependence of silica nanospheres embedded in 385 nm ultraviolet light-emitting diodes on a far-field emission pattern
Author(s) -
Young Jae Park,
Nam Han,
Beo Deul Ryu,
Min Han,
Kang Bok Ko,
Trần Viết Cường,
Jaehee Cho,
Eun–Kyung Suh,
Chang–Hee Hong
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.22.0a1553
Subject(s) - light emitting diode , materials science , optoelectronics , optics , diode , sapphire , ultraviolet , near and far field , wavelength , substrate (aquarium) , epitaxy , laser , nanotechnology , layer (electronics) , physics , oceanography , geology
We demonstrate that the use of silica nanospheres (SNs) with sizes close to the emission wavelength of light-emitting diodes (LEDs) can enhance the light output power and manipulate the far-field emission pattern. Near-ultraviolet (NUV)-LEDs grown on a patterned sapphire substrate embedded with 300 nm SNs show a three times higher light output power than that without SNs, when measured through the top side. For far-field emission measurements, the LEDs embedded with 300 nm SNs show the significant increase of front emission due to the improved crystal quality of epitaxial films as well as the increase of Mie scattering effect of SNs. These experimental results indicate the important role of the size of embedded SNs in enhancing the light output power for NUV-LEDs.