Ground-state electron transfer in all-polymer donor:acceptor blends enables aqueous processing of water-insoluble conjugated polymers

Abstract

Water-based conductive inks are vital for the sustainable manufacturing and widespread adoption of organic electronic devices. Traditional methods to produce waterborne conductive polymers involve modifying their backbone with hydrophilic side chains or using surfactants to form and stabilize aqueous nanoparticle dispersions. However, these chemical approaches are not always feasible and can lead to poor material/device performance. Here, we demonstrate that ground-state electron transfer (GSET) between donor and acceptor polymers allows the processing of water-insoluble polymers from water. This approach enables macromolecular charge-transfer salts with 10,000× higher electrical conductivities than pristine polymers, low work function, and excellent thermal/solvent stability. These waterborne conductive films have technological implications for realizing high-performance organic solar cells, with efficiency and stability superior to conventional metal oxide electron transport layers, and organic electrochemical neurons with biorealistic firing frequency. Our findings demonstrate that GSET offers a promising avenue to develop water-based conductive inks for various applications in organic electronics.

A Highly Conductive n-Type Conjugated Polymer Synthesized in Water

“…The use of the surfactant Tween 80 (TW80) yields more homogeneous films (Figure S13), reaching electrical conductivities as high as 66 S cm –1 (average 48 ± 18 S cm –1 , see Table and Figure S17 for a survey of different surfactants). Despite these values being lower than those measured for PBFDO in DMSO, they are the highest reported for n -type conducting polymers synthesized and processed from water or water/alcohol mixtures − ,, (Figure b) and among the highest for n -type conducting polymers entirely processed in ambient conditions. Remarkably, the electrical conductivity of PDADF synthesized using recycled TMQ-PA is on par with that of PDADF produced using freshly synthesized oxidant (Table , entry 4), highlighting the robustness and effectiveness of the recycling process.…”

“…In addition, all these works resulted in the development of polymers with low electrical conductivity (<10 −3 S cm −1 ). The use of nonconjugated 40 or conjugated 41,42 polymeric dopants enabled the processing of alcohol-or water-based conductive inks with electrical conductivity in the range of 2−8 S cm −1 (Figure 1b). Recently, Tang and co-workers reported on the synthesis of poly(3,7-dihydrobenzo[1,2-b:4,5-b′]difuran-2,6-dione) (PBFDO) in dimethyl sulfoxide (DMSO), demonstrating unprecedented electrical conductivities exceeding 1000 S cm −1 for an n-type polymer.…”

“…In addition, all these works resulted in the development of polymers with low electrical conductivity (<10 –3 S cm –1 ). The use of nonconjugated or conjugated , polymeric dopants enabled the processing of alcohol- or water-based conductive inks with electrical conductivity in the range of 2–8 S cm –1 (Figure b).…”

Red Efficient Perovskite Light-Emitting Diodes Assisted with PEIE

“…20,21 At present, small molecule additives have been extensively studied. 22,23 Polymers like PMMA, 24 PVP, 25 GSET, 26 and PVDF 27 can regulate the crystallization process and enhance the stability of thin films more effectively than volatile and dispersive small molecule additives. In addition, they can be fixed around the perovskite crystal after crystallization to further improve the stability of the films.…”

“…Therefore, reducing the grain size of perovskite films while also carefully passivating defects is a crucial strategy for improving the efficiency of PeLEDs. Various types of organic or inorganic additives are typically introduced into the perovskite precursor solution or antisolvent to simultaneously influence grain growth during the film formation process, passivate the defect, and ultimately achieve device efficiency and stability. , At present, small molecule additives have been extensively studied. , Polymers like PMMA, PVP, GSET, and PVDF can regulate the crystallization process and enhance the stability of thin films more effectively than volatile and dispersive small molecule additives. In addition, they can be fixed around the perovskite crystal after crystallization to further improve the stability of the films.…”