Emeraldine Base Polyaniline as an Alternative to Poly(3,4-ethylenedioxythiophene) as a Hole-Transporting Layer

Abstract

The device physics of bilayer polymer light emitting diodes containing either poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] or ladder‐type methyl‐poly(p‐phenylene) active layers have been determined. The active layer was consistent in thickness and general preparation whilst hole transporting layers spin cast from emeraldine base polyaniline protonated with camphorsulfonic acid, emeraldine base polyaniline protonated with 2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid, and emeraldine base polyaniline protonated with polystyrene sulfonated acid, in various ratios of polyaniline to counter ion, were used in order to determine how various spin‐processible polyaniline layers performed relative to a commercially available polystyrene sulfonated acid doped poly(3,4‐ethylenedioxythiophene layer. For poly[2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylenevinylene] light‐emitting diodes we observe an improvement in performance when using emeraldine base polyaniline protonated with polystyrene sulfonated acid relative to poly(3,4‐ethylenedioxythiophene protonated with polystyrene sulfonated acid, with a maximum device external quantum efficiency of 0.6362 % at a current density of 20.18 mA/cm2.

A facile synthesis of sulfonated poly(diphenylamine) and the application as a novel hole injection layer in polymer light emitting diodes

“…Yang and Heeger [1] utilized metallic salt form of polyaniline (PANI) doped with camphor sulfonic acid (CSA) as HIL. Further reports [6,7] indicated that the work function and the conductivity of PANI could be altered by varying dopants and the doping ratio, affecting the device performance. In fact, polyethylene dioxythiopheneepolystyrene sulphonate (PEDOT:PSS) was commonly used as HIL, due to its superior properties, such as water soluble, environmentally stable, high transparency and great hole-injecting ability [8].…”

“…13 C NMR spectra of neutralized PDPA and SPDPA were obtained on the Bruker AMX-500 spectrometer with resonance frequencies at 125.0 MHz. The neutralized PDPA and SPDPA samples were dissolved in deuterated dimethyl sulfoxide (DMSO-d 6 ) and deuterium oxide (D 2 O), respectively. FT-IR measurements were carried out on Nicolet-550 Fourier Transfer Infrared Spectrometer, and the sample pellets were prepared by mixing powders and KBr.…”

Self‐Organized Gradient Hole Injection to Improve the Performance of Polymer Electroluminescent Devices

“…[2] Interface engineering between the anode and the emitting layer is important for the improvement of the device lifetime as well as luminous efficiency in PLEDs. Previous literature reports described several approaches to interface engineering that resulted in improving the device performances of organic light-emitting diodes, for instance, i) anode modification by plasma treatment, [3,4] ii) chemical modification of the anode, [5][6][7] iii) introducing a hole-injection layer (HIL), [8][9][10][11][12][13][14][15][16][17] and iv) a hole-transporting interlayer between the HIL and emitting layer. [18][19][20] Hole-injecting conducting polymer films such as polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene) (PEDOT) [10][11][12][13] on indium tin oxide (ITO) play important roles to improve the device efficiency and the stability, because they can improve the hole injection from the ITO (work function: ca.…”

Investigation on the Low Luminous Efficiency in a Polymer Light‐Emitting Diode with a High Work‐function Cathode by Soft Contact Lamination**

“…[3] Even if the hole injection is promoted by adding a hole-injection layer on top of the ITO, such as polyaniline doped with camphor sulfonic acid [18][19][20] or PEDOT-PSS, [21] the device quantum efficiency was very similar to the device without the holeinjection layer, as shown in the literature, and has been explained based on the unbalanced charge injection because of the poor electron injection. [19] The experiment in our lab also …”