Understanding the role of ultra-thin polymeric interlayers in improving efficiency of polymer light emitting diodes

Bailey, J. E.; Wright, Edward Needles; Wang, Xuhua; Walker, Alison B.; Bradley, Donal D. C.; Kim, Jinhyun

doi:10.1063/1.4879455

Cited by 15 publications

(17 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, both of the CPE EIL devices produce higher luminance at a given current density than the Ca/Al device (see inset to Note that in all devices tested here, hole injection (and device stability) is optimized by inclusion of a thin TFB interlayer between the PEDOT:PSS coated ITO anode and the F8BT EML. [22][23][24] Figure 2c shows normalized EL spectra of the CPE/Al and Ca/Al devices that suggest that the emission predominantly originates from the F8BT EML. 25 The corresponding photoluminescence (PL) spectra of F8imBT-Br and F8im-Br thin films are distinct from those shown in Figure 2c, peaking at 575 nm for F8imBT-Br and 430 nm for F8im-Br ( Figure S4).…”

Section: Resultsmentioning

confidence: 99%

High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure

Suh

Bailey

Kim

et al. 2015

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

Imidazolium ionic side-group-containing fluorene-based conjugated polyelectrolytes (CPEs) with different π-conjugated structures, poly[(9,9-bis(8'-(3"-methyl-1"-imidazolium)octyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] dibromide (F8im-Br) and poly [(9,9-bis(8'-(3"-methyl-are synthesized and utilized as an electron injection layer (EIL) in green-emitting F8BT polymer light-emitting diodes (PLEDs). Both CPE EIL devices significantly outperform Ca cathode devices; 17.9 cd A -1 (at 3.8 V) and 16.6 lm W -1 (at 3.0 V) for F8imBT-Br devices, 11.1 cd A -1 (at 4.2 V) and 9.1 lm W -1 (at 3.4 V) for F8im-Br devices, and 7.2 cd A -1 (at 3.6 V) and 7.0 lm W -1 (at 3.0 V) for Ca devices. Importantly, unlike the F8im-Br EIL devices, F8imBT-Br PLEDs exhibit much faster electroluminescence turn-on times (< 10 μs) despite both EILs possessing the same tethered imidazolium and mobile bromide ions. The F8imBT-Br devices represent, to the best of our knowledge, the highest efficiency in thin (70 nm) single-layer F8BT PLEDs in conventional device architecture with the fastest EL response time using CPE EIL with mobile ions. Our results clearly indicate the importance of an additional factor of EIL materials, specifically the conjugated backbone structure, to determine the device efficiency and response times.3

show abstract

Section: Resultsmentioning

confidence: 99%

High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure

Suh

Bailey

Kim

et al. 2015

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the non-inverted architecture, where TFB is first cast, the polymer is baked above its glass transition temperature (T g ) to insolubilise the near interfacial region. 5 Likewise, we cast TFB onto F8BT films annealed at 155 1C (T g B 140 1C) for 15 minutes and treated with a cyclohexanone rinse. The TFB wets the F8BT extremely well, as evidenced by a strong purple colour observed on the green F8BT -however the films were still discontinuous ( Fig.…”

Section: F8bt/tfb Bilayer Formationmentioning

confidence: 99%

Fluorene copolymer bilayers for emission colour tuning in inverted hybrid light emitting diodes

2015

View full text Add to dashboard Cite

© The Royal Society of Chemistry 2015.We present a robust, entirely solution-based processing route for the deposition of planar F8BT/TFB poly(9,9-dioctylfluorene-alt-benzothiadiazole)/poly(9,9-dioctylfluorene-alt-N-(4-butylphenyl)-diphenylamine) emissive/hole transport bilayers for emission colour tuning in inverted organic-inorganic hybrid light emitting diodes (HyLEDs). Our method allows the facile exploration of TFB thickness for the first time within inverted devices; here we describe the influence of TFB thickness on the device performance. In particular, we demonstrate significant variations in device electroluminescence with highly controlled tunability between green and orange (550 to 610 nm) emission; correlating directly with the thickness of the TFB layer. These changes are in parallel with a 20-fold increase in current efficiency with respect to F8BT-only devices, with our bilayer devices exhibiting luminance values exceeding 11 000 cd m^-2. Additionally, through reflectance and angle-dependent electroluminescence measurements we explore the presence of microcavity effects and their impact on device behaviour. We introduce TFB not only as a charge blocking/transporting layer but also as an optical emission-tuning layer

show abstract

“…TFB has previously been shown to improve OLED device efficiency by preventing quenching of excitons formed in the emissive layer due to the wide energy gap of the TFB (>3.0 eV) blocking exciton migration, as well as acting as a good hole transporting layer due to its low ionization potential (5.33 eV) and high hole mobility. 18,19 A thermally evaporated small-molecule electron transport layer was not used in these devices to reduce device complexity, thus showing efficient OLED device can be fabricated using solution-processing methods.…”

Section: Resultsmentioning

confidence: 99%

Benzoselenadiazole and benzotriazole directed electrophilic C–H borylation of conjugated donor–acceptor materials

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

Understanding the role of ultra-thin polymeric interlayers in improving efficiency of polymer light emitting diodes

Abstract: Articles you may be interested in Understanding molecular interactions in light-emitting polymer bilayers: The role of solvents and molecular structure on the interface quality Appl.

Cited by 15 publications

References 55 publications

High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure

High-Efficiency Polymer LEDs with Fast Response Times Fabricated via Selection of Electron-Injecting Conjugated Polyelectrolyte Backbone Structure

Fluorene copolymer bilayers for emission colour tuning in inverted hybrid light emitting diodes

Benzoselenadiazole and benzotriazole directed electrophilic C–H borylation of conjugated donor–acceptor materials

Contact Info

Product

Resources

About