Higher Light Extraction Efficiency in Organic Light-Emitting Devices by Employing 2D Periodic Corrugation.

Yu Bai,Yang Wang,Yingzhi Wang,Yahui Chuai

doi:10.3389/fchem.2021.807867

Abstract

Photons trapped in the form of waveguide (WG) modes associated with the organic–organic interface and in the form of surface plasmon polariton (SPP) modes associated with the metallic electrode–organic interface result in a large energy loss in organic light-emitting devices (OLEDs). Introducing gratings onto the metallic electrode is especially crucial for recovering the power lost to the associated SPP modes. In our research, we demonstrate the efficient outcoupling of SPP modes in TE mode by two-dimensional (2D) grating, which cannot excited in one-dimensional (1D) grating OLED. This causes a 62.5% increase in efficiency from 2D grating OLED than 1D grating OLED. The efficient outcoupling of the WG and SPP modes is verified by the numerical simulation of both the emission spectra and the field distribution.

Highlights

In flat panel display and solid-state lighting, organic light-emitting devices (OLEDs) have great application potential
A conducting polymer widely used in polymer LEDs as a hole-transport material, poly(N-vinyl carbazole) (PVK), is chosen, and it is spin-coated on the indium tin oxide (ITO) glass for the fabrication of the corrugated hole transporting layer (HTL) in OLEDs. 4,4′,4′′-Tris(3-methylphenylphe-nylamino) triphenylamine (m-MTDATA) was doped into the PVK with a concentration of 5% by weight to enhance the hole injection and transport of the HTL
When the device structure and other conditions are matched, 2D grating device has significantly better performance than 1D grating device, and this can only be explained by 2D grating having a higher coupling efficiency when it comes to surface plasma and WG mode

Summary

INTRODUCTION

In flat panel display and solid-state lighting, organic light-emitting devices (OLEDs) have great application potential. OLED has many advantages, such as energy efficiency, large viewing angle, low working voltage, fast response, and lightweight. It is considered an ideal solution for future display and light sources. Taking advantage of a higher coupling efficiency of SPP and WG mode in 2D grating structure, we obtained OLED with higher light extraction efficiency (Rigneault et al, 2000; Han et al, 2003; Giannattasio and Barnes, 2005; Jing et al, 2005; Wedge et al, 2005; Yang et al, 2005; Peng et al, 2006)

EXPERIMENT

DISCUSSION

Findings

CONCLUSION

DATA AVAILABILITY STATEMENT