Alcohol-Soluble Conjugated Polymers as Cathode Interlayers for All-Polymer Solar Cells

Abstract

Conjugated polymers with polar side-chain components have successfully been used as cathode interfacial materials (CIMs) to improve the performances of polymer solar cells with fullerenes as acceptors. However, their uses and functions in all-polymer solar cells (all-PSCs) have not been well-investigated. Therefore, in this work, four conjugated polymers bearing different functional side chains, including dimethylamine, diethanolamine, and imidazole, were used as CIMs to study their effects on all-PSCs. With a combination of high-performing acceptor and donor polymers as active layers, the performances of the devices based on the four CIMs were compared with conventional devices with LiF/Al and Al as cathode. Compared to the devices with only Al as cathode, the devices comprising conjugated polymers as CIMs presented large improvement in power conversion efficiency from 2.7% to around 5.3%, which is comparable to the devices with LiF/Al as cathode. The encouraging results demonstrated that the use of conjugated interfacial polymers is a robust way to improve the performances of all-PSCs and can elegantly circumvent the use of low work function metals as cathodes. This is very important for roll-to-roll processing of flexible and large-scale solar cells.

A pyridinium-pended conjugated polyelectrolyte for efficient photocatalytic hydrogen evolution and organic solar cells

“…The better interface modification capability of DPTFBr could be attributed to its pyridinium side chains, which could lower the work function of metal electrode, induce interface doping, etc. 17,[81][82][83][84][85][86] The EQE spectra of the devices were also collected to confirm the obtained J sc values of the DPTFBr-based devices. The calculated J sc values from the EQE curves were compared with the measured values, as summarized in Table 2.…”

Aldol Condensation‐Polymerized n‐Doped Conjugated Polyelectrolytes for High‐Performance Nonfullerene Polymer Solar Cells

“…Therefore, it can be expected that PFBP-Br and PFBP-I can assist the formation of good energy alignment and ohmic contact at the cathode of NF-PSCs. [68,69] However, for the PFBP-BArF 4 modified Ag electrode, the work function was raised to 4.78 eV. Compared with other CPEs, a reverse dipole is formed between BArF 4 À and the Ag electrode, which leads to the raised work force (WF) of the Ag electrode modified by PFBP-BArF 4 , [41,70] suggesting that PFBP-BArF 4 modified-Ag electrode might not be a proper candidate of ETM for NF-PSCs.…”

Polyrhodamine: a redox stable conducting polyelectrolyte

“…As such, they are used in optoelectronic devices, [1][2][3] optical sensing (chemo-and biosensors), 4 and biological imaging. 5 In addition, they find application as interfacial layer materials in organic electronic devices, such as organic light-emitting diodes (OLEDs), [6][7][8] organic field-effect transistors (OFETs), 9 and organic photovoltaic cells (OPVCs), 10 leading to substantial improvement in the performance of these devices. CPEs usually have a hydrophobic backbone made from conjugated polymers such as polythiophene, poly( p-phenylene), and polyfluorene with hydrophilic sidechains that contain either cationic, anionic, or zwitterionic groups.…”