Enhanced light extraction from organic light-emitting devices using a sub-anode grid (Presentation Recording)

Yue Qu; Michael Slootsky; Stephen Forrest

doi:10.1117/12.2187295

5 October 2015 Enhanced light extraction from organic light-emitting devices using a sub-anode grid (Presentation Recording)

Yue Qu, Michael Slootsky, Stephen Forrest

Author Affiliations +

Proceedings Volume 9566, Organic Light Emitting Materials and Devices XIX; 95661C (2015) https://doi.org/10.1117/12.2187295
Event: SPIE Organic Photonics + Electronics, 2015, San Diego, California, United States

Abstract

We demonstrate a method for extracting waveguided light trapped in the organic and indium tin oxide layers of bottom emission organic light emitting devices (OLEDs) using a patterned planar grid layer (sub-anode grid) between the anode and the substrate. The scattering layer consists of two transparent materials with different refractive indices on a period sufficiently large to avoid diffraction and other unwanted wavelength-dependent effects. The position of the sub-anode grid outside of the OLED active region allows complete freedom in varying its dimensions and materials from which it is made without impacting the electrical characteristics of the device itself. Full wave electromagnetic simulation is used to study the efficiency dependence on refractive indices and geometric parameters of the grid. We show the fabrication process and characterization of OLEDs with two different grids: a buried sub-anode grid consisting of two dielectric materials, and an air sub-anode grid consisting of a dielectric material and gridline voids. Using a sub-anode grid, substrate plus air modes quantum efficiency of an OLED is enhanced from (33±2)% to (40±2)%, resulting in an increase in external quantum efficiency from (14±1)% to (18±1)%, with identical electrical characteristics to that of a conventional device. By varying the thickness of the electron transport layer (ETL) of sub-anode grid OLEDs, we find that all power launched into the waveguide modes is scattered into substrate. We also demonstrate a sub-anode grid combined with a thick ETL significantly reduces surface plasmon polaritons, and results in an increase in substrate plus air modes by a >50% compared with a conventional OLED. The wavelength, viewing angle and molecular orientational independence provided by this approach make this an attractive and general solution to the problem of extracting waveguided light and reducing plasmon losses in OLEDs.

Conference Presentation

Citation Download Citation

Yue Qu, Michael Slootsky, and Stephen Forrest "Enhanced light extraction from organic light-emitting devices using a sub-anode grid (Presentation Recording)", Proc. SPIE 9566, Organic Light Emitting Materials and Devices XIX, 95661C (5 October 2015); https://doi.org/10.1117/12.2187295

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available