Engineering a Poly(3,4-ethylenedioxythiophene):(Polystyrene Sulfonate) Surface Using Self-Assembling Molecules—A Chemical Library Approach

Abstract

The surface properties of poly(3,4-ethylenedioxythiophene):(polystyrene sulfonate) (PEDOT:PSS) affect the performance of many organic electronic devices. The work function determines the efficiency of the charge carrier transfer between PEDOT:PSS electrodes and the active layer of the device. The surface free energy affects phase separation in multicomponent blends that are typically used to fabricate active layers of organic light-emitting diodes and photovoltaic devices. Here, we present a method to prepare PEDOT:PSS films with a gradient work function and surface free energy. This modification was achieved by evaporation of trimethoxy(3,3,3-trifluoropropyl)silane in such a way that the degree of surface coverage of the molecules varied in the selected direction. Gradient films were used as electrodes to fabricate two-terminal PEDOT:PSS/poly(3-hexyl thiophene)/Au devices to rapidly screen for the influence of the modification on the performance of the prepared polymer diodes. Gradual changes in the morphology of the solution-cast model poly(3-butyl thiophene)/poly-bromostyrene films followed changes in the surface energy of the substrate.

PEDOT:PSS in Water and Toluene for Organic Devices—Technical Approach

“…In recent years, poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS), especially with regard to its use in electronic devices including photovoltaics, received interest on account of its relatively simple processability at low temperature, antireflecting properties, and water-based dispersion [24][25][26][27]. In some devices, water-free PEDOT:PSS is required, mainly due to the design of the layer deposition process via evaporation from toluene solution or the vulnerability of some components to moisture, i.e., in the construction of perovskite solar cells [28][29][30].…”

Controlling the Cyano‐Containing A2 Segments in A2‐A1‐D‐A1‐A2 Type Non‐Fullerene Acceptors to Combine with a Benzotriazole‐Based p‐Type Polymer: “Same‐Acceptor‐Strategy” for High VOC Organic Solar Cells

“…Therefore, the investigation of the intermolecular forces of the active layer surface can further help to explain the different device performance. Up to now, a few attentions have been paid to the impact of surface free energy on the microstructure of the active layer …”

“…Up to now, a few attentions have been paid to the impact of surface free energy on the microstructure of the active layer. [53,[57][58] The neutral water and nonpolar methylene diiodide were selected as the test solvents because they cannot dissolve the blend films, have large surface free energy and different surface free energy components. [59] According to the previously reported method described in the supporting information, we have calculated the surface free energy of J71, BTA3, BTA703 and their blend films through measuring their contact angles with methylene diiodide and water as imaged in Figure 8 and listed in Table 4.…”

Rising advancements in the application of PEDOT:PSS as a prosperous transparent and flexible electrode material for solution-processed organic electronics

“…Another approach to patterning PEDOT:PSS as an ordered thin-film structure for application in organic electronic devices suggests the use of self-assembled monolayers (SAMs) for the modification of the surface free energy and morphology of the polymer to effectively adjust its W f for better energy level matching between the polymer electrodes and the active layers of the devices [117,118].…”