Showing papers on "Fullerene published in 2023"

Y‐Type Non‐Fullerene Acceptors with Outer Branched Side Chains and Inner Cyclohexane Side Chains for 19.36% Efficiency Polymer Solar Cells

Abstract: Raising the lowest unoccupied molecular orbital (LUMO) energy level of Y‐type non‐fullerene acceptors can increase the open‐circuit voltage (Voc) and thus the photovoltaic performance of the current top performing polymer solar cells (PSCs). One of the viable routes is demonstrated by the successful Y6 derivative of L8‐BO with the branched alkyl chains at the outer side. This will introduce steric hindrance and reduce intermolecular aggregation, thus open up the bandgap and raise the LUMO energy level. To take further advantages of the steric hindrance influence on optoelectronic properties of Y6 derivatives, two Y‐type non‐fullerene acceptors of BTP‐Cy‐4F and BTP‐Cy‐4Cl are designed and synthesized by adopting outer branched side chains and inner cyclohexane side chains. An outstanding Voc of 0.937 V is achieved in the D18:BTP‐Cy‐4F binary blend devices along with a power conversion efficiency (PCE) of 18.52%. With the addition of BTP‐eC9 to extend the absorption spectral coverage, a remarkable PCE of 19.36% is realized finally in the related ternary blend devices, which is one of the highest values for single‐junction PSCs at present. The results illustrate the great potential of cyclohexane side chains in constructing high‐performance non‐fullerene acceptors and their PSCs.

19.31% binary organic solar cell and low non-radiative recombination enabled by non-monotonic intermediate state transition

Abstract: Non-fullerene acceptors based organic solar cells represent the frontier of the field, owing to both the materials and morphology manipulation innovations. Non-radiative recombination loss suppression and performance boosting are in the center of organic solar cell research. Here, we developed a non-monotonic intermediate state manipulation strategy for state-of-the-art organic solar cells by employing 1,3,5-trichlorobenzene as crystallization regulator, which optimizes the film crystallization process, regulates the self-organization of bulk-heterojunction in a non-monotonic manner, i.e., first enhancing and then relaxing the molecular aggregation. As a result, the excessive aggregation of non-fullerene acceptors is avoided and we have achieved efficient organic solar cells with reduced non-radiative recombination loss. In PM6:BTP-eC9 organic solar cell, our strategy successfully offers a record binary organic solar cell efficiency of 19.31% (18.93% certified) with very low non-radiative recombination loss of 0.190 eV. And lower non-radiative recombination loss of 0.168 eV is further achieved in PM1:BTP-eC9 organic solar cell (19.10% efficiency), giving great promise to future organic solar cell research.

Fullerene Lattice‐Confined Ru Nanoparticles and Single Atoms Synergistically Boost Electrocatalytic Hydrogen Evolution Reaction

Abstract: The design and construction of electrocatalysts with high efficiency, low cost and large current output suitable for industrial hydrogen production is the current development trend for water electrolysis. Herein, a lattice‐confined in situ reduction effect of the 3D crystalline fullerene network (CFN) is developed to trap Ru nanoparticle (NP) and single atom (SA) via a solvothermal‐pyrolysis process. The optimized product (RuNP‐RuSA@CFN‐800) exhibits outstanding electrocatalytic performance for alkaline hydrogen evolution reactions. To deliver a current density of 10 mA cm−2, the RuNP‐RuSA@CFN‐800 merely required an overpotential of 33 mV, along with a robust electrocatalytic durability for 1400 h. Even at large current densities of 500 and 1000 mA cm−2, the overpotentials are only 154 and 251 mV, respectively. Density function theorey calculation results indicated that the electronic synergetic effect between Ru NP and SA enable to regulate the charge distribution of RuNP‐RuSA@CFN‐800 and reduce the Gibbs free energy of intermediate species for water dissociation process, thereby accelerating the hydrogen evolution process. Moreover, the robust CFN matrix render this strategy patulous to other transition metals, e.g., Cu, Ni, and Co. The present study provides a new clue for the construction of novel electrocatalyst in the field of energy storage and conversion.

Enhancing Built-in Electric Fields for Efficient Photocatalytic Hydrogen Evolution by Encapsulating C60 Fullerene into Zirconium-Based Metal-Organic Frameworks.

Abstract: High-efficiency photocatalysts based on metal-organic frameworks (MOFs) are often limited by poor charge separation and slow charge transfer kinetics. Herein, a novel MOF photocatalyst is successfully constructed by encapsulating C60 into a nano-sized Zirconium-based MOF, NU-901. By virtue of host-guest interactions and uneven charge distribution, a substantial electrostatic potential difference is set-up in C60@NU-901. The direct consequence is a robust built-in electric field, which tends to be in C60@NU-901 10.7 times higher than that found in NU-901. Driven by it, photogenerated charge carriers are efficiently separated and transported to the surface. For example, photocatalytic hydrogen evolution reaches 22.3 mmol g-1 h-1 for C60@NU-901, which is among the highest values for MOFs. Our concept of enhancing charge separation by harnessing host-guest interactions constitutes a promising strategy to design photocatalysts for efficient solar-to-chemical energy conversion.

Fullerene trigged energy storage and photocatalytic ability of La2O3-ZnO@C60 core-shell nanocomposite

Abstract: Fullerene (C60)-based carbon materials are attracting the attention of researchers because of their large surface area, three-dimensional structure, tunable architectures, and high chemical stability. In this study, the core–shell nanocomposite of lanthanum oxide (La2O3), zinc oxide (ZnO), and C60 was prepared via the solution method. Transmission electron microscope (TEM) images confirmed the development of core–shell with La2O3-ZnO (core) and C60 (shell). The photodegradation test against methylene blue (MB) dye showed complete degradation after 40 min. The electrochemical performance of La2O3[email protected]60 exposed large pseudo-capacitance, reversible Faradic charge-storage mechanism, and outstanding cyclic stability (93 % retention after 1000th cycle) and exhibited superior specific capacitance of 2135 F/g at 0.05 A/g with a remarkable energy density of 47.44 Wh/kg at the power density of 2.26 KW/kg. Thus, La2O3[email protected]60 displayed dual functions, such as energy storage materials for next-generation supercapacitor electrodes and an efficient photocatalyst.

A Comprehensive Compilation of Graphene/Fullerene Polymer Nanocomposites for Electrochemical Energy Storage

Abstract: Electricity consumption is an integral part of life on earth. Energy generation has become a critical topic, addressing the need to fuel the energy demands of consumers. Energy storage is an offshoot of the mainstream process, which is now becoming a prime topic of research and development. Electrochemical energy storage is an attractive option, serving its purpose through fuel cells, batteries and supercapacitors manipulating the properties of various materials, nanomaterials and polymer substrates. The following review presents a comprehensive report on the use of carbon-based polymer nanocomposites, specifically graphene and fullerene-based polymer nanocomposites, towards electrochemical energy storage. The achievements in these areas, and the types of polymer nanocomposites used are listed. The areas that lack of clarity and have a dearth of information are highlighted. Directions for future research are presented and recommendations for fully utilizing the benefits of the graphene/fullerene polymer nanocomposite system are proposed.

Stability and Elasticity of Quasi-Hexagonal Fullerene Monolayer from First-Principles Study

Abstract: As a newly synthesized two-dimensional carbon material, the stability study of monolayer fullerene networks or quasi-hexagonal phase fullerenes (qhp-C60) is timely desirable. We have investigated the stabilities of qhp-C60, including thermal, structural, mechanical, and thermodynamic stabilities, as well as the bonding characteristics, ductility, and mechanical properties, via first-principles calculations. The results show that qhp-C60 is energetically, mechanically, and thermodynamically stable. The thermodynamic stability of qhp-C60 at 300 K and 600 K is verified. The bonding characteristics of qhp-C60 are analyzed from the bond length, and it has sp2 and sp3 hybridization. The Pugh ratio (B/G) and Poisson’s ratio (v) indicate similar ductility with graphite and graphene. We also found that qhp-C60 has the lowest hardness and the anisotropy of the material. In addition, the electronic characteristics, including electron localization function (ELF), crystal orbital Hamiltonian population (COHP), and density of states (DOS) at different temperatures, are analyzed to verify the thermal stability of the material. Our results might be helpful in the material design of qhp-C60-related applications.

Carbon nanomaterials advancements for biomedical applications

Abstract: The development of new technologies has helped tremendously in delivering timely, appropriate, acceptable, and reasonably priced medical treatment. Because of developments in nanoscience, a new class of nanostructures has emerged. Nanomaterials, because of their small size, display exceptional physio-chemical capabilities such as enhanced absorption and reactivity, increased surface area, molar extinction coefficients, tunable characteristics, quantum effects, and magnetic and optical properties. Researchers are interested in carbon-based nanomaterials due to their unique chemical and physical properties, which vary in thermodynamic, biomechanical, electrical, optical, and structural aspects. Due to their inherent properties, carbon nanomaterials, including fullerenes, graphene, carbon nanotubes (CNTs), and carbon nanofibers (CNFs), have been intensively studied for biomedical applications. This article is a review of the most recent findings about the development of carbon-based nanomaterials for use in biosensing, drug delivery, and cancer therapy, among other things.

Theoretical framework for achieving high Voc in non-fused non-fullerene terthiophene-based end-capped modified derivatives for potential applications in organic photovoltaics

Abstract: Non-fused ring-based OSCs are an excellent choice, which is attributed to their low cost and flexibility in applications. However, developing efficient and stable non-fused ring-based OSCs is still a big challenge. In this work, with the intent to increase Voc for enhanced performance, seven new molecules derived from a pre-existing A–D–A type A3T-5 molecule are proposed. Different important optical, electronic and efficiency-related attributes of molecules are studied using the DFT approach. It is discovered that newly devised molecules possess the optimum features required to construct proficient OSCs. They possess a small band gap ranging from 2.22–2.29 eV and planar geometries. Six of seven newly proposed molecules have less excitation energy, a higher absorption coefficient and higher dipole moment than A3T-5 in both gaseous and solvent phases. The A3T-7 molecule exhibited the maximum improvement in optoelectronic properties showing the highest λmax at 697 nm and the lowest Ex of 1.77 eV. The proposed molecules have lower ionization potential values, reorganization energies of electrons and interaction coefficients than the A3T-5 molecule. The Voc of six newly developed molecules is higher (Voc ranging from 1.46–1.72 eV) than that of A3T-5 (Voc = 1.55 eV). Similarly, almost all the proposed molecules except W6 exhibited improvement in fill factor compared to the A3T-5 reference. This remarkable improvement in efficiency-associated parameters (Voc and FF) proves that these molecules can be successfully used as an advanced version of terthiophene-based OSCs in the future.

Superior thermoelectric properties of bulk and monolayer fullerene networks

Abstract: In this paper, the structure and electronic energy band of bulk and monolayer fullerene (C60) networks are analyzed in detail, stimulated by successfully experimental synthesis of C60 networks [Hou L,...

Non-covalently linked donor-acceptor interaction enhancing photocatalytic hydrogen evolution from porphyrin assembly

Abstract: The separation of photogenerated excitons plays a crucial role in initiating high-efficiency photocatalysis of organic semiconductors. Herein, a non-covalent donor-acceptor (D-A) structure composed of tetrakis (4-carboxyphenyl) zinc porphyrin (ZnTCPP) linked to ethylenediamine functionalized fullerene (C60-EDA) by electrostatic interaction was successfully developed. Due to D-A interaction, an efficient electron transfer channel from ZnTCPP to C60-EDA was established, resulting in a charge-separated state with appreciable lifetime. Accordingly, the photogenerated excitons separation got considerably improved and charge-carrier exhibited faster migration to the surface of D-A assembly. ZnTCPP/C60-EDA presented efficient photocatalytic H2 evolution of 113.5 μmol h−1 under full spectrum, 3.9 times higher that of pure ZnTCPP. This work offers valuable insight into the non-covalent D-A construction for enhanced photocatalytic performance.

Molecular orientation-dependent energetic shifts in solution-processed non-fullerene acceptors and their impact on organic photovoltaic performance

Abstract: The non-fullerene acceptors (NFAs) employed in state-of-art organic photovoltaics (OPVs) often exhibit strong quadrupole moments which can strongly impact on material energetics. Herein, we show that changing the orientation of Y6, a prototypical NFA, from face-on to more edge-on by using different processing solvents causes a significant energetic shift of up to 210 meV. The impact of this energetic shift on OPV performance is investigated in both bilayer and bulk-heterojunction (BHJ) devices with PM6 polymer donor. The device electronic bandgap and the rate of non-geminate recombination are found to depend on the Y6 orientation in both bilayer and BHJ devices, attributed to the quadrupole moment-induced band bending. Analogous energetic shifts are also observed in other common polymer/NFA blends, which correlates well with NFA quadrupole moments. This work demonstrates the key impact of NFA quadruple moments and molecular orientation on material energetics and thereby on the efficiency of high-performance OPVs.

Functionalized Fullerenes and Their Applications in Electrochemistry, Solar Cells, and Nanoelectronics

Abstract: Carbon-based nanomaterials have rapidly advanced over the last few decades. Fullerenes, carbon nanotubes, graphene and its derivatives, graphene oxide, nanodiamonds, and carbon-based quantum dots have been developed and intensively studied. Among them, fullerenes have attracted increasing research attention due to their unique chemical and physical properties, which have great potential in a wide range of applications. In this article, we offer a comprehensive review of recent progress in the synthesis and the chemical and physical properties of fullerenes and related composites. The review begins with the introduction of various methods for the synthesis of functionalized fullerenes. A discussion then follows on their chemical and physical properties. Thereafter, various intriguing applications, such as using carbon nanotubes as nanoreactors for fullerene chemical reactions, are highlighted. Finally, this review concludes with a summary of future research, major challenges to be met, and possible solutions.

Solution Aggregate Structures of Donor Polymers Determine the Morphology and Processing Resiliency of Non-Fullerene Organic Solar Cells

Abstract: The solution-state aggregation of conjugated polymers is critical to the morphology and device performance of bulk heterojunction (BHJ) organic solar cells (OSCs). However, the detailed structures of polymer solution-state aggregates and their impact on the morphology and device performance of OSCs remain largely unexplored. Herein, we utilize a benzodithiophene-based donor polymer (PM7) and its ester-functionalized derivatives (PM7 D1 and D2) with reduced backbone rigidity as our model systems to demonstrate how a polymer solution-state aggregate structure impacts the morphology and processing resiliency of OSCs. Using X-ray scattering and microscopic imaging techniques, we ascertain that PM7 solution forms a combination of semi-crystalline fiber aggregates and amorphous polymer chain network aggregates, whereas PM7 D1 and D2 solutions primarily form amorphous network aggregates through sidechain associations. Interestingly, when the solution temperature is increased, the fiber aggregates of PM7 break down while the polymer network aggregates remain stable. Due to this temperature-dependent behavior of the fiber aggregates, blade-coated devices fabricated from the PM7 donor polymer and non-fullerene acceptor, ITIC-4F, lead to highly processing temperature-sensitive performance, whereas PM7 D1 and D2 polymers exhibit improved processing temperature resiliency. More importantly, we report that amorphous, network-like aggregates are conducive to superior device performance in blade-coated OSCs owing to the formation of blend films with short π–π stacking distance, small domain spacing, and face-on preferred molecular orientation. In contrast, we find that fiber-like aggregates lead to large π–π stacking distance, large domain spacing, and isotropic molecular orientation in the blend film, which deteriorate the device performance.