Conducting polymers, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been widely used as the hole injection layer (HIL) in many applications. However, in OLEDs the commonly used PEDOT:PSS has been found to have serious problems due to its inefficient holeinjection, inefficient electron-blocking, and substantial quenching of excitons close to the PEDOT:PSS. In the literature, tetrafluoroethylene-perfluoro-3,6-dioxa-4-methyl-7-octene-sulfonic acid copolymer, one of perfluorinated ionomers (PFI), was introduced into the PEDOT:PSS layer to develop a gradient work function (WF) by self-organization of the PFI. In this contribution, the self-organized gradient effect of this novel PEDOT:PSS:PFI layer were studied using multiscale analysis and dissipative particle dynamics (DPD) simulation. The DPD inter particle repulsion parameters and intramolecular bonding parameters were obtained by reverse mapping of a series of molecular dynamics simulations similar to that used in the earlier contributions. The calculated Flory-Huggins parameters indicated that the Nafion portion of the copolymer attracts PSS while the entire PFI molecule repulses PEDOT, which results in a PFI rich interface and a vertical gradient concentration distribution of PEDOT along the vertical direction of the film layer.
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