Evolution of nanomorphology and anisotropic conductivity in solvent-modified PEDOT:PSS films for polymeric anodes of polymer solar cells

Transverse charge transport in inkjet printed poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS)

“…Na et al [10] found that the ratio of the in-plane to transverse conductivities of spin coated PEDOT:PSS films varied from 60 to 10 for 0 to 3 % DMSO, reducing to 6 for 11% DMSO, which still amounted to a very low value of transverse conductivity of 0.02 S cm -1 .…”

“…It is clear that processing methods of using a co-solvent and annealing, although improving the in-plane conductivity of PEDOT:PSS [8][9][10], do not raise sufficiently the transverse conductivity of PEDOT:PSS. Nardes et al [11] investigated the mechanism of charge transport in in-plane and transverse conduction for spin coated PEDOT:PSS films.…”

“…Addition of co-solvent, such as DMSO [8][9][10], ethylene glycol [15] or sorbitol [16], leads to the evolution of the in-plane conduction to 1D-M-VRH model of charge transport for both spin coated and inkjet printed [9] PEDOT:PSS films, which explains the higher in-plane conductivity of PEDOT:PSS with a co-solvent [4, 8-10, 15, 16-17]. However, the effect of inkjet printing on the transverse conductivity of PEDOT:PSS has not been investigated yet, although inkjet printing has yielded OPVs of high efficiency [18] and increase of the spin coating speed has improved conjugation and efficiency in PLEDs (polymer LEDs) [19].…”

Designs and Architectures for the Next Generation of Organic Solar Cells

“…They reported an OSC of 1.5% PCE using high conductivity PEDOT:PSS (treated with meso-erythritol). Admassie et al Starck), it's conductivity can also be increased by adding DMSO [41]. In order to gain a better understanding of the nature of solvent-modified PEDOT:PSS films and the origin of its increased conductivity, they investigated changes in conductivity, morphology, surface composition, workfunction, and anisotropic conductivity in both parallel and perpendicular directions of DMSO treated PEDOT:PSS films.…”

“…Finding alternatives to ITO is a major area of research in the last five years. Some of the alternatives are doped metal oxides [33][34][35][36][37], organic polymers [38][39][40][41][42][43], metal grids [44][45][46][47], carbon nanotubes [48][49][50][51] and graphene [52,53]. [37].…”