Glycol Side Chains Research Articles

Efficient N-Type Organic Electrochemical Transistors and Field-Effect Transistors Based on PNDI-Copolymers Bearing Fluorinated Selenophene-Vinylene-Selenophenes.

n-Type organic electrochemical transistors (OECTs) and organic field-effect transistors (OFETs) are less developed than their p-type counterparts. Herein, polynaphthalenediimide (PNDI)-based copolymers bearing novel fluorinated selenophene-vinylene-selenophene (FSVS) units as efficient materials for both n-type OECTs and n-type OFETs are reported. The PNDI polymers with oligo(ethylene glycol) (EG7) side chains P(NDIEG7-FSVS), affords a high µC* of > 0.2Fcm-1 V-1 s-1 , outperforming the benchmark n-type Pg4NDI-T2 and Pg4NDI-gT2 by two orders of magnitude. The deep-lying LUMO of -4.63eV endows P(NDIEG7-FSVS) with an ultra-low threshold voltage of 0.16V. Moreover, the conjugated polymer with octyldodecyl (OD) side chains P(NDIOD-FSVS) exhibits a surprisingly low energetic disorder with an Urbach energy of 36meV and an ultra-low activation energy of 39meV, resulting in high electron mobility of up to 0.32cm2 V-1 s-1 in n-type OFETs. These results demonstrate the great potential for simultaneously achieving a lower LUMO and a tighter intermolecular packing for the next-generation efficient n-type organic electronics.

Characterizing Conformational Change of a Thermoresponsive Polymeric Nanoparticle with Raman Spectroscopy

Molecular conformational changes in the collapsing and reswelling processes occurring during the phase transition at the lower critical solution temperature (LCST) of the polymer are not well understood. In this study, we characterized the conformational change of Poly(oligo(Ethylene Glycol) Methyl Ether Methacrylate)-144 (POEGMA-144) synthesized on silica nanoparticles using Raman spectroscopy and zeta potential measurements. Changes in distinct Raman peaks associated with the oligo(Ethylene Glycol) (OEG) side chains (1023, 1320, and 1499 cm−1) with respect to the methyl methacrylate (MMA) backbone (1608 cm−1) were observed and investigated under increasing and decreasing temperature profiles (34 °C to 50 °C) to evaluate the polymer collapse and reswelling around its LCST (42 °C). In contrast to the zeta potential measurements that monitor the change in surface charges as a whole during the phase transition, Raman spectroscopy provided more detailed information on vibrational modes of individual molecular moieties of the polymer in responding to the conformational change.

The Nanostructured Self-Assembly and Thermoresponsiveness in Water of Amphiphilic Copolymers Carrying Oligoethylene Glycol and Polysiloxane Side Chains.

Amphiphilic copolymer self-assembly is a straightforward approach to obtain responsive micelles, nanoparticles, and vesicles that are particularly attractive for biomedicine, i.e., for the delivery of functional molecules. Here, amphiphilic copolymers of hydrophobic polysiloxane methacrylate and hydrophilic oligo (ethylene glycol) methyl ether methacrylate with different lengths of oxyethylenic side chains were synthesized via controlled RAFT radical polymerization and characterized both thermally and in solution. In particular, the thermoresponsive and self-assembling behavior of the water-soluble copolymers in water was investigated via complementary techniques such as light transmittance, dynamic light scattering (DLS), and small-angle X-ray scattering (SAXS) measurements. All the copolymers synthesized were thermoresponsive, displaying a cloud point temperature (Tcp) strongly dependent on macromolecular parameters such as the length of the oligo(ethylene glycol) side chains and the content of the SiMA counits, as well as the concentration of the copolymer in water, which is consistent with a lower critical solution temperature (LCST)-type behavior. SAXS analysis revealed that the copolymers formed nanostructures in water below Tcp, whose dimension and shape depended on the content of the hydrophobic components in the copolymer. The hydrodynamic diameter (Dh) determined by DLS increased with the amount of SiMA and the associated morphology at higher SiMA contents was found to be pearl-necklace-micelle-like, composed of connected hydrophobic cores. These novel amphiphilic copolymers were able to modulate thermoresponsiveness in water in a wide range of temperatures, including the physiological temperature, as well as the dimension and shape of their nanostructured assemblies, simply by varying their chemical composition and the length of the hydrophilic side chains.

Side-Chain Modification in Conjugated Polymer Frameworks for the Electrocatalytic Oxygen Evolution Reaction.

Conjugated polymer frameworks (CPFs) have recently sparked tremendous research interest due to their broad potentials in various frontline application areas such as photocatalysis, sensing, gas storage, energy storage, etc. These framework materials, without sidechains or functional groups on their backbone, are generally insoluble in common organic solvents and less solution processable for further device applications. There are few reports on metal-free electrocatalysis, especially oxygen evolution reaction (OER) using CPF. Herein, we have developed two triazine-based donor-acceptor conjugated polymer frameworks by coupling a 3-substituted thiophene (donor) unit with a triazine ring (acceptor) through a phenyl ring spacer. Two different sidechains, alkyl and oligoethylene glycol, were rationally introduced into the 3-position of thiophene in the polymer framework to investigate the effect of side-chain functionality on the electrocatalytic property. Both the CPFs demonstrated superior electrocatalytic OER activity and long-term durability. The electrocatalytic performance of CPF2, which achieved a current density of 10 mA/cm2 at an overpotential (η) of 328 mV, is much superior to CPF1, which reached the same current density at an overpotential of 488 mV. The porous and interconnected nanostructure of the conjugated organic building blocks, which allowed for fast charge and mass transport processes, could be attributed to the higher electrocatalytic activity of both CPFs. However, the superior activity of CPF2 compared to CPF1 may be due to the presence of a more polar oxygen-containing ethylene glycol side chain, which enhances the surface hydrophilicity, promotes better ion/charge and mass transfer, and increases the accessibility of the active sites toward adsorption through lower π-π stacking compared to hexyl side chain present in CPF1. The DFT study also supports the plausible better performance toward OER for CPF2. This study confirms the promising potentiality of metal-free CPF electrocatalysts for OER and further sidechain modification to improve their electrocatalytic property.

Mechanically Adaptive Mixed Ionic-Electronic Conductors Based on a Polar Polythiophene Reinforced with Cellulose Nanofibrils.

Conjugated polymers with oligoether side chains are promising mixed ionic-electronic conductors, but they tend to feature a low glass transition temperature and hence a low elastic modulus, which prevents their use if mechanical robust materials are required. Carboxymethylated cellulose nanofibrils (CNF) are found to be a suitable reinforcing agent for a soft polythiophene with tetraethylene glycol side chains. Dry nanocomposites feature a Young's modulus of more than 400 MPa, which reversibly decreases to 10 MPa or less upon passive swelling through water uptake. The presence of CNF results in a slight decrease in electronic mobility but enhances the ionic mobility and volumetric capacitance, with the latter increasing from 164 to 197 F cm-3 upon the addition of 20 vol % CNF. Overall, organic electrochemical transistors (OECTs) feature a higher switching speed and a transconductance that is independent of the CNF content up to at least 20 vol % CNF. Hence, CNF-reinforced conjugated polymers with oligoether side chains facilitate the design of mechanically adaptive mixed ionic-electronic conductors for wearable electronics and bioelectronics.

Solution Characterization of PEGL, a Water-Soluble, Non-Ionic, Helical Polypeptide

In this work, a non-ionic, water-soluble rigid rod polymer was investigated for viability in replacing organic-soluble rigid rod polymers as these legacy rigid polymers require difficult solvents. Producing a rigid, water-soluble polymer that does not suffer from aggregation or ionic effects is a difficult proposition. Herein, the synthesis of a poly(lysine) with a short ethylene glycol side chain, PEGL, was duplicated, based on previous work by Deming et al. and characterized by various techniques. It was discovered that PEGL suffers from aggregation, evidenced by dynamic and static light scattering experiments that showed non-ideal rigid rod behavior and multiple decay rates. PEGL also showed a changing lower critical solution temperature when varying salt concentration. Although PEGL can exhibit a double helix conformation and has non-ionic side chains, the propensity for aggregation precludes PEGL from being used for fundamental polymer investigation.

Double Doping of Semiconducting Polymers Using Ion‐Exchange with a Dianion

AbstractThe interactions between counterions and electronic carriers in electrically doped semiconducting polymers are important for delocalization of charge carriers, electronic conductivity, and thermal stability. The introduction of a dianions in semiconducting polymers leads to double doping where there is one counterion for two charge carriers. Double doping minimizes structural distortions, but changes the electrostatic interactions between the carriers and counterions. Polymeric ionic liquids (PIL) with croconate dianions are helpful to investigate the role of the counterion in p‐type semiconducting polymers. PILs prevent diffusion of the cation into the semiconducting polymers during ion exchange. The redox‐active croconate dianions undergo ion exchange with doped semiconducting polymers depending on their ionization energy. Croconate dianions are found to reduce doped films of poly(3‐hexyl thiophene), but undergo ion exchange with a polythiophene with tetraethylene glycol side chains, P(g42T‐T), that has a lower ionization energy. The croconate dianion maintains crystalline order in P(g42T‐T) and leads to a lower activation energy for the electrical conductivity than PF6− counterions. The control of the doping level with croconate allows optimization of the thermoelectric performance of the semiconducting polymer. The thermal stability of the doped films of P(g42T‐T) is found to depend strongly on the nature of the counterion.

Remote Control of One‐Handed Helicity in Polyacetylenes through Flexible Spacers in Water: Impact of the Spacer Length

AbstractWe report the unprecedented sergeants and soldiers (S&S)‐type remote control of one‐handed helicity in copolymers of chiral/achiral biphenylylacetylenes bearing amphiphilic oligo(ethylene glycol) (OEG) side chains. A small amount of chiral binaphthyl residues (≤10 mol %) introduced at the terminal of the achiral OEG spacers as many as 80 bonds away from the polymer backbones induced a complete one‐handed helix in water through preferential intramolecular encapsulation of the binaphthyl groups within a cavity of the copolymers. A fully one‐handed helix can be induced virtually independent of the OEG spacer length and concentrations. At a specific spacer length, however, its helix‐sense was inverted. The copolymers also form an excess one‐handed helix in organic solvents in an OEG spacer‐length dependent manner, yet far from the polymer backbones. We show the superiority of the present covalent‐bond driven S&S‐type remote helicity control over the corresponding noncovalent helicity induction approach.

Remote Control of One-Handed Helicity in Polyacetylenes through Flexible Spacers in Water: Impact of the Spacer Length.

We report the unprecedented sergeants and soldiers (S&S)-type remote control of one-handed helicity in copolymers of chiral/achiral biphenylylacetylenes bearing amphiphilic oligo(ethylene glycol) (OEG) side chains. A small amount of chiral binaphthyl residues (≤10 mol %) introduced at the terminal of the achiral OEG spacers as many as 80 bonds away from the polymer backbones induced a complete one-handed helix in water through preferential intramolecular encapsulation of the binaphthyl groups within a cavity of the copolymers. A fully one-handed helix can be induced virtually independent of the OEG spacer length and concentrations. At a specific spacer length, however, its helix-sense was inverted. The copolymers also form an excess one-handed helix in organic solvents in an OEG spacer-length dependent manner, yet far from the polymer backbones. We show the superiority of the present covalent-bond driven S&S-type remote helicity control over the corresponding noncovalent helicity induction approach.

Surface-Enriched Amphiphilic Polysiloxane Coating with Superior Antifouling Ability and Strong Substrate Adhesion

The coexistence of superior antifouling ability and strong substrate adhesion is a typical trade-off for a silicone coating but is highly desirable in numerous applications. Herein, we present a surface-enriched antifouling coating consisting of a bis-silane-terminated polyurea (SPU), an oligosiloxane nanocluster, and a bi-silanol-terminated poly(dimethylsiloxane) with fluorocarbon and poly(ethylene glycol) side chains as a reactive amphiphilic polymer (RAP). The oligosiloxane nanoclusters can cross-link the flexible SPU into a tough polymer network and interlink the polymer network to the substrate, whereas the low-surface-energy RAP can self-enrich on the surface during coating formation. Such a polysiloxane coating exhibits high transparency (>85% transmittance), high tensile strength (∼12 MPa), superior fouling resistance against proteins and bacteria, and strong adhesion strength on various substrates including glass, ceramic, steel, Ti, and epoxy (3–15 MPa). This research provides a universal and tunable approach for the future design of antifouling coatings in flexible electronics, medical devices, and marine industries.

Engineering the Hydrophobic Microenvironment in Polystyrene-Supported Artificial Catalytic Triad Nanocatalysts: An Effective Strategy for Improving Catalytic Performance

Hydrophobic environments have been identified as one of the main parameters affecting the catalytic performance of artificial catalytic triads but are often ignored as an approach to engineering these catalysts. Here, we have developed a simple yet powerful strategy to engineer the hydrophobic environment in polystyrene-supported artificial catalytic triad (PSACT) nanocatalysts. Hydrophobic copolymers containing either oligo(ethylene glycol) side chains or hydrocarbon side chains were synthesized and used for the preparation of nanocatalysts through nanoprecipitation in aqueous media. By using the hydrolysis of 4-nitrophenyl acetate (4NA) as a model reaction, we studied the influence of chemical structures and effective constituent ratios of hydrophobic copolymers on the catalytic performance of PSACT nanocatalysts. Additionally, PSACT nanocatalysts could catalyze the hydrolysis of a few carboxylic esters, even polymers, and be reused for five consecutive runs without significant loss of catalytic activity. This strategy may open an avenue for engineering other artificial enzymes, and these PSACT nanocatalysts have potential applications for the hydrolysis of carboxylic esters.

Side-Chain Engineering in Hydrophilic n-Type π-Conjugated Polymers for Enhanced Reactivity

Minor changes to side chains in conjugated polymers (CPs) can have pronounced effects on polymer properties by altering backbone planarity, solubility, and interaction with ions. Here, we report the photocontrolled synthesis of hydrophilic CPs from Grignard monomers and find that switching from alkyl to oligo(ethylene glycol) (OEG) side chains changes their photoreactivity. Specifically, installing hydrophilic side chains on the same monomer core yields higher molecular weight polymers and allows polymerization to proceed with lower-energy red light. Additionally, we discover a side chain decomposition pathway for N-OEG monomers, which are prevalent in CP research. Decomposition can be overcome by adding an extra methylene unit in the side chains without compromising polymer molecular weight or hydrophilicity. Importantly, this polymerization does not require transition metal catalysts and is a promising approach to the preparation of n-type conjugated block copolymers.

Ion Size-Dependent Electrochromism in Air-Stable Napthalenediimide-Based Conjugated Polymers.

Conjugated polymers (CPs) that show stable and reversible cation insertion/deinsertion under ambient conditions hold great potential for optoelectronic and energy storage devices. However, n-doped CPs are prone to parasitic reactions upon exposure to moisture or oxygen. This study reports a new family of napthalenediimide (NDI) based conjugated polymers capable of undergoing electrochemical n-type doping in ambient air. By functionalizing the NDI-NDI repeating unit with alternating triethylene glycol and octadecyl side chains, the polymer backbone shows stable electrochemical doping at ambient conditions. We systematically investigate the extent of volumetric doping involving monovalent cations of varying size (Li+, Na+, tetraethylammonium (TEA+)) with electrochemical methods, including cyclic voltammetry, differential pulse voltammetry, spectroelectrochemistry, and electrochemical impedance spectroscopy. We observed that introducing hydrophilic side chains on the polymer backbone improves the local dielectric environment of the backbones and lowers the energetic barrier for ion insertion. Surprisingly, when using Na+ electrolyte, the polymer films exhibit higher volumetric doping efficiency, faster-switching kinetics, higher optical contrast, and selective multielectrochromism when compared to Li+ or TEA+ electrolytes. Using well-tempered metadynamics, we characterize the free energetics of side chain-ion interactions to find that Li+ binds more tightly to the glycolated NDI moieties than Na+, hindering Li+ ion transport, switching kinetics, and limiting the films' doping efficiency.

Toughening Ionic Polymer Using Bulky Alkylammonium Counterions and Comb Architecture.

Ionic interactions in ionic polymers, such as ionomers, polyelectrolytes, and polyampholytes, contribute to toughness in systems with high mobility and active ion dynamics, such as hydrogels and elastomers. However, it remains challenging to toughen rigid polymers through ionic interactions without lowering their elastic modulus through plasticization. Here, we present a strategy for toughening without sacrificing the elastic modulus by combining a comb polymer with bulky ammonium counterions. We designed and synthesized ionic comb polymers with oligoethylene glycol side chains and carboxylic acids in each monomer unit of the polynorbornene backbone, neutralized by trialkylamines, ranging from ethyl to octyl. The counterion size in ionic comb polymers influenced the mechanical properties of tensile testing─not the elongation at break and the elastic modulus but the ultimate strength and toughness. The ionic comb polymer containing heptylammonium counterions displayed the highest toughness of 77 MJ m-3. Tensile studies at various strain rates demonstrated a rate-dependent difference between heptyl- and octylammonium counterions. This result suggests that the heptylammonium counterion acted as a sacrificial bond by providing a moderate dissociation rate that was slightly slower than that of the octylammonium counterion, leading to toughening.

Oligo(ethylene glycol) Side Chain Architecture Enables Alcohol-Processable Conjugated Polymers for Organic Solar Cells

Achieving green-solvent solubility of conjugated polymers in truly green solvents such as alcohols has proven to be a significant challenge. In this work, we report the synthesis and characterization of three conjugated polymers derived from poly[(thiophene)-alt-(6,7-difluoro-2-(2-hexyldecyloxy)quinoxaline)] (PTQ10) with the goal of developing derivates which are more green-solvent-processable. The traditional alkyl side chains are replaced by various oligo(ethylene glycol) (OEG) side chains of different architectures, including one linear and two branched, all of which contain six ethylene glycol repeating units. It is determined that the linear OEG side chain architecture, even when sufficiently long, will not give desired green-solvent solubility shown by a small solubility capacity (R0). However, branched OEG side chains significantly improve solubility as R0 was increased from 4.7 of PTQ10 to 11.9 of PTQ-6bO/6bO2. Although the solution states of the polymers were vastly different, the solid-state morphologies were more similar as all three OEG-based polymers retained a predominately face-on molecular orientation similar to PTQ10. It was demonstrated that PTQ-6O devices showed the most comparable power conversion efficiencies (PCEs) to PTQ10 in bulk heterojunction solar cells, while PTQ-6bO2 and PTQ-6bO showed poorer performances. With one extra carbon in the side chain, PTQ-6bO2 showed higher PCE than PTQ-6bO, attributed to the improved aggregation properties and solid-state morphology of PTQ-6bO2, highlighting the importance of OEG side chain architecture. This work serves to develop important guidelines for future alcohol-soluble materials for green-solvent-processed OPVs.

Effects of Different Lengths of Oligo (Ethylene Glycol) Side Chains on the Electrochromic and Photovoltaic Properties of Benzothiadiazole-Based Donor-Acceptor Conjugated Polymers.

In recent years, donor-acceptor (D-A)-type conjugated polymers have been widely used in the field of organic solar cells (OSCs) and electrochromism (EC). Considering the poor solubility of D-A conjugated polymers, the solvents used in material processing and related device preparation are mostly toxic halogenated solvents, which have become the biggest obstacle to the future commercial process of the OSC and EC field. Herein, we designed and synthesized three novel D-A conjugated polymers, PBDT1-DTBF, PBDT2-DTBF, and PBDT3-DTBF, by introducing polar oligo (ethylene glycol) (OEG) side chains of different lengths in the donor unit benzodithiophene (BDT) as side chain modification. Studies on solubility, optics, electrochemical, photovoltaic and electrochromic properties are conducted, and the influence of the introduction of OEG side chains on its basic properties is also discussed. Studies on solubility and electrochromic properties show unusual trends that need further research. However, since PBDT-DTBF-class polymers and acceptor IT-4F failed to form proper morphology under the low-boiling point solvent THF solvent processing, the photovoltaic performance of prepared devices is not ideal. However, films with THF as processing solvent showed relatively desirable electrochromic properties and films cast from THF display higher CE than CB as the solvent. Therefore, this class of polymers has application feasibility for green solvent processing in the OSC and EC fields. The research provides an idea for the design of green solvent-processable polymer solar cell materials in the future and a meaningful exploration of the application of green solvents in the field of electrochromism.

Interactions of Catalytic Enzymes with n-Type Polymers for High-Performance Metabolite Sensors.

The tight regulation of the glucose concentration in the body is crucial for balanced physiological function. We developed an electrochemical transistor comprising an n-type conjugated polymer film in contact with a catalytic enzyme for sensitive and selective glucose detection in bodily fluids. Despite the promise of these sensors, the property of the polymer that led to such high performance has remained unknown, with charge transport being the only characteristic under focus. Here, we studied the impact of the polymer chemical structure on film surface properties and enzyme adsorption behavior using a combination of physiochemical characterization methods and correlated our findings with the resulting sensor performance. We developed five n-type polymers bearing the same backbone with side chains differing in polarity and charge. We found that the nature of the side chains modulated the film surface properties, dictating the extent of interactions between the enzyme and the polymer film. Quartz crystal microbalance with dissipation monitoring studies showed that hydrophobic surfaces retained more enzymes in a densely packed arrangement, while hydrophilic surfaces captured fewer enzymes in a flattened conformation. X-ray photoelectron spectroscopy analysis of the surfaces revealed strong interactions of the enzyme with the glycolated side chains of the polymers, which improved for linear side chains compared to those for branched ones. We probed the alterations in the enzyme structure upon adsorption using circular dichroism, which suggested protein denaturation on hydrophobic surfaces. Our study concludes that a negatively charged, smooth, and hydrophilic film surface provides the best environment for enzyme adsorption with desired mass and conformation, maximizing the sensor performance. This knowledge will guide synthetic work aiming to establish close interactions between proteins and electronic materials, which is crucial for developing high-performance enzymatic metabolite biosensors and biocatalytic charge-conversion devices.

Mixed Ionic-Electronic Conduction Increases the Rate Capability of Polynaphthalenediimide for Energy Storage.

Conjugated polymers offer a number of unique and useful properties for use as battery electrodes, and recent work has reported that conjugated polymers can exhibit excellent rate performance due to electron transport along the polymer backbone. However, the rate performance depends on both ion and electron conduction, and strategies for increasing the intrinsic ionic conductivities of conjugated polymer electrodes are lacking. Here, we investigate a series of conjugated polynapthalene dicarboximide (PNDI) polymers containing oligo(ethylene glycol) (EG) side chains that enhance ion transport. We produced PNDI polymers with varying contents of alkylated and glycolated side chains and investigated the impact on rate performance, specific capacity, cycling stability, and electrochemical properties through a series of charge-discharge, electrochemical impedance spectroscopy, and cyclic voltammetry measurements. We find that the incorporation of glycolated side chains results in electrode materials with exceptional rate performance (up to 500C, 14.4 s per cycle) in thick (up to 20 μm), high-polymer-content (up to 80 wt %) electrodes. Incorporation of EG side chains enhances both ionic and electronic conductivities, and we found that PNDI polymers with at least 90% of NDI units containing EG side chains functioned as carbon-free polymer electrodes. This work demonstrates that polymers with mixed ionic and electronic conduction are excellent candidates for battery electrodes with good cycling stability and capable of ultra-fast rate performance.

Aqueous-alcohol-processable indolo[3,2-b]indole-based crystalline small molecules for organic field effect transistors with oligo(ethylene glycol) side chains

We address an eco-friendly aqueous process approach to obtain efficient/stable small molecule organic field effect transistors (OFETs). Penta-ethylene glycol (PEG) side chains were introduced at N-positions of the rigid backbone structures of indolo[3,2-b]indole(IDID), thus enabling the formation of PEG-IDIDF. The PEG-IDIDF exhibited remarkable solubility in alcohol (ethanol) solvent. The X-ray diffraction and grazing incidence wide angle X-ray scattering measurements indicate that the suitable addition of a typical cosolvent, water, to ethanol solvent significantly contributes to an enhancement in film crystallinity and molecular stacking orientation features than those of the PEG-IDIDF film processed by using a single solvent. Consequently, the PEG-IDIDF OFETs processed by the ethanol water cosolvent (90:10) ratio yielded the enhanced hole mobility of 4.07 × 10−3 cm2 V−1 s−1 and current on/off ratio of 106, which was one of the highest reliable mobility for small molecules OFETs processed with an alcohol solvent.

A Triethyleneglycol C60 Mono‐adduct Derivative for Efficient Electron Transport in Inverted Perovskite Solar Cells†

Comprehensive SummaryInverted perovskite solar cells (PSCs) have attracted increasing attention in recent years owing to their low‐temperature fabrication proces s. However, they suffer from a limited number of electron transport materials available with [6,6]‐phenyl C61 butyric acid methyl ester (PCBM) to be the most widely studied based on its appropriate energy levels and high electron mobility. The low relative permittivity and aggregation tendency upon illumination of PCBM, however, compromises the solar cell efficiency whereas its modest hydrophobicity negatively impacts on the device stability. Alternative electron transport materials with desired properties and appropriate degree of hydrophobicity are thus desirable for further developments in inverted PSCs. Herein, we synthesize a triethyleneglycol C60 mono‐adduct derivative (termed as EPF03) and test it as a novel electron transport material to replace PCBM in inverted PSCs based on a quadruple cation (RbCsMAFA) perovskite. We also compare this derivative with two novel fullerenes decorated with two (EPF01) or one dodecyl (EPF02) long side chains. The latter two fail to perform efficiently in inverted PSCs whereas the former enabled a power conversion efficiency of 18.43%, which represents a 9% improvement compared to the reference device using PCBM (17.21%). The enhanced performance mainly stems from improved electron extraction and reduced recombination enabled by the insertion of the large relative permittivity amongst other properties of EPF03. Furthermore, our results indicate that triethylene glycol side chains can also passivate perovskite trap states, suppress ion migration and enhance photostability and long‐term stability of EPF03 based perovskite solar cells.