Title: Simulation of enhanced light extraction from periodic, disordered, and quasi-periodic OLED structures

Abstract

We have developed a rigorous scattering matrix theory of light emission from periodically structured media using a Green’s function approach. We computationally simulate the spectral power inside the structure, incorporating Purcell factor enhancements, and find internal waveguiding modes and plasmonic losses. We simulate the light-outcoupling factor ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}$ and describe how corrugations and structured media can enhance ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}$ . We have extended our framework to describe non-periodic disordered arrays as well as aperiodic quasi-crystalline arrays. Flat organic light-emitting diodes (OLEDs) have low outcoupling with ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}\sim \; <\#comment/>20\mathrm{\%\; <\#comment/>}$ since most of the light is trapped in waveguided modes in higher index layers or lost to plasmonic excitations at the metal cathode. Periodically corrugated OLEDs can achieve highly enhanced ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}\sim \; <\#comment/>65\mathrm{\%\; <\#comment/>}-\; <\#comment/>70\mathrm{\%\; <\#comment/>}$ for pitch values between 1000 and 2000 nm, representing an enhancement factor $>\; <\#comment/>3$ over planar structures. Periodic corrugations strongly diffract trapped waveguided and plasmonic modes to the emissive air cone. Disordered templates also can cause significant enhanced outcoupling with ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}\sim \; <\#comment/>50\mathrm{\%\; <\#comment/>}-\; <\#comment/>55\mathrm{\%\; <\#comment/>}$ for smaller nearest-neighbor separations of 300–400 nm. Quasi-crystalline tilings can also lead to enhancements of ${\mathrm{\eta \; <\#comment/>}}_{\text{out}}\sim \; <\#comment/>50\mathrm{\%\; <\#comment/>}-\; <\#comment/>55\mathrm{\%\; <\#comment/>}$ . This framework can be utilized to design novel structured media that can generate high light extraction.

Authors:

Zhang, Yu ^[1]; Biswas, Rana  ^[2];

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• Search DOE PAGES for ORCID "0000-0002-0866-2100"

Shinar, Ruth ^[1]; Shinar, Joseph ^[2]

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+ Show Author Affiliations

1. Iowa State University, Ames, IA (United States)
2. Ames Laboratory, and Iowa State University, Ames, IA (United States)

Publication Date:

Mon Aug 09 00:00:00 EDT 2021

Research Org.:

Iowa State Univ., Ames, IA (United States)

Sponsoring Org.:

USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:

1848537

Alternate Identifier(s):

OSTI ID: 1812245; OSTI ID: 1812246

Grant/Contract Number:  

EE0007621; EE0008724; AC02-05CH11231

Resource Type:

Accepted Manuscript

Journal Name:

Journal of the Optical Society of America. Part B, Optical Physics

Additional Journal Information:

Journal Volume: 38; Journal Issue: 9; Journal ID: ISSN 0740-3224

Publisher:

Optical Society of America (OSA)

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING