Light extraction from surface plasmons and waveguide modes in an organic light-emitting layer by nanoimprinted gratings.
Organic light-emitting diodes (OLEDs) usually exhibit a low light outcoupling efficiency because a large fraction of power is lost to surface plasmons (SPs) and waveguide modes. In this paper it is demonstrated that periodic grating structures with almost µm-scale can be used to extract SPs as well as waveguide modes and therefore enhance the outcoupling efficiency in light-emitting thin film structures. The gratings are fabricated by nanoimprint lithography using a commercially available diffraction grating as a mold which is pressed into a polymer resist. The outcoupling of SPs and waveguide modes is detected in fluorescent organic films adjacent to a thin metal layer in angular dependent photoluminescence measurements. Scattering up to 5th-order is observed and the extracted modes are identified by comparison to the SP and waveguide dispersion obtained from optical simulations. In order to demonstrate the low-cost, high quality and large area applicability of grating structures in optoelectronic devices, we also present SP extraction using a grating structure fabricated by a common DVD stamp.
Institute of Physics, University of Augsburg, Universitätsstrasse 1, 86159 Augsburg, Germany. joerg.frischeisen@physik.uni-augsburg.de
Jörg
J
Frischeisen
Quan
Q
Niu
Alaa
A
Abdellah
Jörg B
JB
Kinzel
Robert
R
Gehlhaar
Giuseppe
G
Scarpa
Chihaya
C
Adachi
Paolo
P
Lugli
Wolfgang
W
Brütting
D000465:Algorithms; D004581:Electronics; D005456:Fluorescent Dyes / Q000737:chemistry; D008027:Light; D049449:Luminescence; D018625:Microscopy, Atomic Force / Q000379:methods; D015233:Models, Statistical; D036103:Nanotechnology / Q000379:methods*; D055095:Optics and Photonics; D009930:Organic Chemicals / Q000737:chemistry; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*
D005456:Fluorescent Dyes; D009930:Organic Chemicals