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

Journal Article · Mon Aug 09 00:00:00 EDT 2021 · Journal of the Optical Society of America. Part B, Optical Physics

DOI:https://doi.org/10.1364/josab.430593· OSTI ID:1848537

Zhang, Yu ^[1]; Biswas, Rana  ^[2]; Shinar, Ruth ^[1]; Shinar, Joseph ^[2]

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

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.

• Research Organization: Iowa State Univ., Ames, IA (United States)
• Sponsoring Organization: USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: EE0007621; EE0008724; AC02-05CH11231
• OSTI ID: 1848537
• Alternate ID(s): OSTI ID: 1812245; OSTI ID: 1812246
• Journal Information: Journal of the Optical Society of America. Part B, Optical Physics, Vol. 38, Issue 9; ISSN 0740-3224
• Publisher: Optical Society of America (OSA)
• Country of Publication: United States
• Language: English

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