A generic surfactant-free approach to overcome wetting limitations and its application to improve inkjet-printed P3HT:non-fullerene acceptor PV

Abstract

A novel strategy to overcome wetting problems is applied to manufacture inverted structure P3HT:O-IDTBR solar cells with 5% efficiency.

Ink Engineering of Transport Layers for 9.5% Efficient All‐Printed Semitransparent Nonfullerene Solar Cells

“…[ 12 ] Since the successful demonstration of all inkjet‐printed solar cells with a PCE of 4.1% by Eggenhuisen et al. in 2015, [ 23 ] there have been some studies that have centered on the optimization of hole transport layers (HTLs) that can coat on top of the highly hydrophobic PALs, [ 24–26 ] and current collectors that compete with their evaporated counterparts while providing added properties such as semitransparency.…”

“…These scalable efforts have worked well for PALs based on P3HT in combination with fullerene derivatives or the NFA O‐IDTBR in an inverted architecture. [ 24,25,27 ] However, the energy levels of P3HT limit the full potential of novel high‐performance low bandgap NFAs such as IEICO‐4F, which can be better utilized alongside push‐pull type donor polymers like PTB7‐Th to yield ultrahigh photocurrents and efficiencies over 12%. [ 28–30 ] Several works have focused on the specific development of HTLs in NFA‐based devices but they rely on the utilization of complex surface modifiers, [ 31,32 ] dipole layers, [ 33–35 ] or HTL materials that cannot yet be used for stable inverted structures or in scale‐up processes.…”

Flexible All‐Solution‐Processed Organic Solar Cells with High‐Performance Nonfullerene Active Layers

“…Adding surfactants to the PEDOT:PSS has been adopted to improve its wettability 36. However, the added surfactants tend to aggregate on the surface of the active layer and inhibit the hole extraction 37. 2) A deep‐lying highest occupied molecular orbital (HOMO) level.…”

“…We also tested another active layer (PBDB‐T‐2F:IT‐4F) with this device structure, and the cells with the PEDOT:PSS PH1000 top electrodes also exhibited poorer performance ( V OC = 0.70 V, J SC = 17.0 mA cm −2 , FF = 0.59, PCE = 7.0%) compared with the reference electrodes ( V OC = 0.84 V, J SC = 18.9 mA cm −2 , FF = 0.75, PCE = 11.8%, Figure S3, Supporting Information). The poor performance can be ascribed to two issues: 1) The surfactant tended to aggregate at the interface, that hindering the efficient charge transport from the active layer to the PEDOT:PSS electrode;37 and 2) the Fermi level of the PEDOT:PSS was not sufficiently deep to form an efficient electrical contact with the deep HOMO level of the polymer donor (PBDB‐T‐2F).…”

Nonlinear dynamics of two-layer channel flow with soluble surfactant below or above the critical micelle concentration

“…The equilibrium and dynamic surface tension behaviour of surfactants is important in a range of processes and applications, as it can influence foam fabrication and stability (Petkova, Tcholakova & Denkov 2012), affect wettability in coatings (Weinstein & Ruschak 2004) (e.g. in photographic applications Maisch et al 2019) and control film deformation (Afsar-Siddiqui, Luckham & Matar 2003). The latter property of surfactants is also significant in multilayer flows, where surfactants can be used to manipulate deformations at fluid–fluid interfaces – this is possible due to the dynamic variation of surface tension and resulting Marangoni forces (e.g.…”