{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:53:18Z","timestamp":1760241198041,"version":"build-2065373602"},"reference-count":84,"publisher":"MDPI AG","issue":"24","license":[{"start":{"date-parts":[[2019,12,8]],"date-time":"2019-12-08T00:00:00Z","timestamp":1575763200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Novel C60 and C70 N-methyl-fulleropyrrolidine derivatives, containing both electron withdrawing and electron donating substituent groups, were synthesized by the well-known Prato reaction. The corresponding highest occupied molecular orbital (HOMO)\/lowest unoccupied molecular orbital (LUMO) energy levels were determined by cyclic voltammetry, from the onset oxidation and reduction potentials, respectively. Some of the novel fullerenes have higher LUMO levels than the standards PC61BM and PC71BM. When tested in PffBT4T-2OD based polymer solar cells, with the standard architecture ITO\/PEDOT:PSS\/Active-Layer\/Ca\/Al, these fullerenes do not bring about any efficiency improvements compared to the standard PC71BM system, however they show how the electronic nature of the different substituents strongly affects the efficiency of the corresponding organic photovoltaic (OPV) devices. The functionalization of C70 yields a mixture of regioisomers and density functional theory (DFT) calculations show that these have systematically different electronic properties. This electronic inhomogeneity is likely responsible for the lower performance observed in devices containing C70 derivatives. These results help to understand how new fullerene acceptors can affect the performance of OPV devices.<\/jats:p>","DOI":"10.3390\/ma12244100","type":"journal-article","created":{"date-parts":[[2019,12,9]],"date-time":"2019-12-09T05:54:51Z","timestamp":1575870891000},"page":"4100","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["PffBT4T-2OD Based Solar Cells with Aryl-Substituted N-Methyl-Fulleropyrrolidine Acceptors"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7063-8462","authenticated-orcid":false,"given":"Hugo","family":"Gaspar","sequence":"first","affiliation":[{"name":"IPC\/i3N\u2014Institute for Polymers and Composites, University of Minho, Campus de Azur\u00e9m, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3685-9736","authenticated-orcid":false,"given":"Fl\u00e1vio","family":"Figueira","sequence":"additional","affiliation":[{"name":"QOPNA &amp; LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8733-9012","authenticated-orcid":false,"given":"Karol","family":"Struty\u0144ski","sequence":"additional","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"Manuel","family":"Melle-Franco","sequence":"additional","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5313-4016","authenticated-orcid":false,"given":"Dzmitry","family":"Ivanou","sequence":"additional","affiliation":[{"name":"LEPABE, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal"}]},{"given":"Jo\u00e3o P. C.","family":"Tom\u00e9","sequence":"additional","affiliation":[{"name":"QOPNA &amp; LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"},{"name":"CQE and Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8392-9581","authenticated-orcid":false,"given":"Carlos M.","family":"Pereira","sequence":"additional","affiliation":[{"name":"CIQUP, Department of Chemistry and Biochemistry, University of Porto, Rua do Campo Alegre, w\/n, 4169-007 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5482-0715","authenticated-orcid":false,"given":"Luiz","family":"Pereira","sequence":"additional","affiliation":[{"name":"Department of Physics and i3N\u2014Institute for Nanostructures, Nanomodelling and Nanofabrication, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2472-3265","authenticated-orcid":false,"given":"Ad\u00e9lio","family":"Mendes","sequence":"additional","affiliation":[{"name":"LEPABE, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal"}]},{"given":"J\u00falio C.","family":"Viana","sequence":"additional","affiliation":[{"name":"IPC\/i3N\u2014Institute for Polymers and Composites, University of Minho, Campus de Azur\u00e9m, 4800-058 Guimar\u00e3es, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7392-4915","authenticated-orcid":false,"given":"Gabriel","family":"Bernardo","sequence":"additional","affiliation":[{"name":"LEPABE, Department of Chemical Engineering, University of Porto, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Gaspar, H., Figueira, F., Pereira, L., Mendes, A., Viana, C.J., and Bernardo, G. (2018). Recent Developments in the Optimization of the Bulk Heterojunction Morphology of Polymer: Fullerene Solar Cells. Materials, 11.","DOI":"10.3390\/ma11122560"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"720","DOI":"10.1038\/s41560-018-0181-5","article-title":"Material insights and challenges for non-fullerene organic solar cells based on small molecular acceptors","volume":"3","author":"Zhang","year":"2018","journal-title":"Nat. Energy"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1038\/s41566-018-0104-9","article-title":"Next-generation organic photovoltaics based on non-fullerene acceptors","volume":"12","author":"Cheng","year":"2018","journal-title":"Nat. Photonics"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"119","DOI":"10.1038\/nmat5063","article-title":"Organic solar cells based on non-fullerene acceptors","volume":"17","author":"Hou","year":"2018","journal-title":"Nat. Mater."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1016\/j.solmat.2016.11.024","article-title":"Review: Fullerene based acceptors for efficient bulk heterojunction organic solar cell applications","volume":"161","author":"Ganesamoorthy","year":"2017","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/S1369-7021(12)70019-6","article-title":"Roll-to-roll fabrication of polymer solar cells","volume":"15","author":"Sondergaard","year":"2012","journal-title":"Mater. Today"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1562","DOI":"10.1016\/j.scib.2017.11.003","article-title":"Ternary organic solar cells offer 14% power conversion efficiency","volume":"62","author":"Xiao","year":"2017","journal-title":"Sci. Bull."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7159","DOI":"10.1021\/jacs.8b02695","article-title":"A Wide Band Gap Polymer with a Deep Highest Occupied Molecular Orbital Level Enables 14.2% Efficiency in Polymer Solar Cells","volume":"140","author":"Li","year":"2018","journal-title":"J. Am. Chem. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"8","DOI":"10.1038\/s41467-019-10351-5","article-title":"Over 16% efficiency organic photovoltaic cells enabled by a chlorinated acceptor with increased open-circuit voltages","volume":"10","author":"Cui","year":"2019","journal-title":"Nat. Commun."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1126\/science.aat2612","article-title":"Organic and solution-processed tandem solar cells with 17.3% efficiency","volume":"361","author":"Meng","year":"2018","journal-title":"Science"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"4653","DOI":"10.1021\/ma500829r","article-title":"Side Chain Selection for Designing Highly Efficient Photovoltaic Polymers with 2D-Conjugated Structure","volume":"47","author":"Zhang","year":"2014","journal-title":"Macromolecules"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1002\/aenm.201501400","article-title":"Influence of Processing Parameters and Molecular Weight on the Morphology and Properties of High-Performance PffBT4T-2OD:PC71BM Organic Solar Cells","volume":"5","author":"Ma","year":"2015","journal-title":"Adv. Energy Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"5293","DOI":"10.1038\/ncomms6293","article-title":"Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells","volume":"5","author":"Liu","year":"2014","journal-title":"Nat. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"44269","DOI":"10.1038\/srep44269","article-title":"Understanding and controlling morphology evolution via DIO plasticization in PffBT4T-2OD\/PC71BM devices","volume":"7","author":"Zhang","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"19023","DOI":"10.1039\/C8CP02195C","article-title":"Effect of fullerene acceptor on the performance of solar cells based on PffBT4T-2OD","volume":"20","author":"Zhang","year":"2018","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"405","DOI":"10.1039\/C7CC08947C","article-title":"Unique cohesive nature of the \u03b21-isomer of [70]PCBM fullerene on structures and photovoltaic performances of bulk heterojunction films with PffBT4T-2OD polymers","volume":"54","author":"Umeyama","year":"2018","journal-title":"Chem. Commun."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"7821","DOI":"10.1002\/adma.201601197","article-title":"Bulk-Heterojunction Organic Solar Cells: Five Core Technologies for Their Commercialization","volume":"28","author":"Kang","year":"2016","journal-title":"Adv. Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1185","DOI":"10.1039\/C0CS00045K","article-title":"Influence of blend microstructure on bulk heterojunction organic photovoltaic performance","volume":"40","author":"Brabec","year":"2011","journal-title":"Chem. Soc. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"45","DOI":"10.1039\/B510618B","article-title":"Morphology of polymer\/fullerene bulk heterojunction solar cells","volume":"16","author":"Hoppe","year":"2006","journal-title":"J. Mater. Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"532","DOI":"10.1021\/jo00108a012","article-title":"Preparation and characterization of fulleroid and methanofullerene derivatives","volume":"60","author":"Hummelen","year":"1995","journal-title":"J. Org. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1789","DOI":"10.1126\/science.270.5243.1789","article-title":"Polymer photovoltaic cells-Enhanced efficiencies via a network of internal donor-acceptor heterojunctions","volume":"270","author":"Yu","year":"1995","journal-title":"Science"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3371","DOI":"10.1002\/anie.200351647","article-title":"Efficient methano 70 fullerene\/MDMO-PPV bulk heterojunction photovoltaic cells","volume":"42","author":"Wienk","year":"2003","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3427","DOI":"10.1021\/jz501559q","article-title":"Influence of Molecular Shape on Solid-State Packing in Disordered PC61BM and PC71BM Fullerenes","volume":"5","author":"Williams","year":"2014","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"71","DOI":"10.1016\/j.solmat.2011.09.006","article-title":"Influence of PC60BM or PC70BM as electron acceptor on the performance of polymer solar cells","volume":"97","author":"Zhang","year":"2012","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"18231","DOI":"10.1021\/acsami.6b02671","article-title":"Revealing the Effect of Additives with Different Solubility on the Morphology and the Donor Crystalline Structures of Organic Solar Cells","volume":"8","author":"Zhao","year":"2016","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"12733","DOI":"10.1039\/C6CC06072B","article-title":"Photochemical site-selective synthesis of [70]methanofullerenes","volume":"52","author":"Vidal","year":"2016","journal-title":"Chem. Commun."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"999","DOI":"10.2174\/1570179414666161230152314","article-title":"Modification on Fullerene","volume":"14","author":"Liu","year":"2017","journal-title":"Curr. Org. Synth."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"594","DOI":"10.1080\/03602559.2016.1233278","article-title":"Advances in Polymer\/Fullerene Nanocomposite: A Review on Essential Features and Applications","volume":"56","author":"Kausar","year":"2017","journal-title":"Polym. Plast. Technol. Eng."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1800941","DOI":"10.1002\/advs.201800941","article-title":"Hybrids of Fullerenes and 2D Nanomaterials","volume":"6","author":"Chen","year":"2019","journal-title":"Adv. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4161","DOI":"10.1039\/c2jm15126j","article-title":"Functional fullerenes for organic photovoltaics","volume":"22","author":"Li","year":"2012","journal-title":"J. Mater. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"054107","DOI":"10.1063\/1.4927476","article-title":"Consistent structures and interactions by density functional theory with small atomic orbital basis sets","volume":"143","author":"Grimme","year":"2015","journal-title":"J. Chem. Phys."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1021\/acs.jpca.8b10240","article-title":"Performance of DFT for C60 Isomerization Energies: A Noticeable Exception to Jacob\u2019s Ladder","volume":"123","author":"Karton","year":"2019","journal-title":"J. Phys. Chem. A"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1021\/jp208520v","article-title":"Photophysical and Electronic Properties of Five PCBM-like C60 Derivatives: Spectral and Quantum Chemical View","volume":"116","author":"Wang","year":"2012","journal-title":"J. Phys. Chem. A"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"155416","DOI":"10.1103\/PhysRevB.72.155416","article-title":"First-principles calculations of the electronic structure of one-dimensional C-60 polymers","volume":"72","author":"Beu","year":"2005","journal-title":"Phys. Rev. B"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1002\/wcms.81","article-title":"The ORCA program system","volume":"2","author":"Neese","year":"2012","journal-title":"Wiley Interdiscip. Rev. Comput. Mol. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5221","DOI":"10.1016\/0040-4020(96)00126-3","article-title":"Synthesis and electrochemical properties of substituted fulleropyrrolidines","volume":"52","author":"Prato","year":"1996","journal-title":"Tetrahedron"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"5432","DOI":"10.1002\/chem.201002318","article-title":"Synthesis and Photoinduced Energy- and Electron-Transfer Processes of C60\u2013Oligothienylenevinylene\u2013C70 Dumbbell Compounds","volume":"17","author":"Urbani","year":"2011","journal-title":"Chem. A Eur. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"7327","DOI":"10.1038\/ncomms8327","article-title":"High-performance ternary blend polymer solar cells involving both energy transfer and hole relay processes","volume":"6","author":"Lu","year":"2015","journal-title":"Nat. Commun."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"20713","DOI":"10.1039\/C9TA06929A","article-title":"16.7%-efficiency ternary blended organic photovoltaic cells with PCBM as the acceptor additive to increase the open-circuit voltage and phase purity","volume":"7","author":"Pan","year":"2019","journal-title":"J. Mater. Chem. A"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2499","DOI":"10.1021\/jo991710u","article-title":"Modification of Regioselectivity in Cycloadditions to C70 under Microwave Irradiation","volume":"65","author":"Langa","year":"2000","journal-title":"J. Org. Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2046","DOI":"10.1021\/acs.accounts.9b00159","article-title":"Isomer Effects of Fullerene Derivatives on Organic Photovoltaics and Perovskite Solar Cells","volume":"52","author":"Umeyama","year":"2019","journal-title":"Acc. Chem. Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"18316","DOI":"10.1039\/C8RA02896F","article-title":"cis-1 Isomers of tethered bismethano 70 fullerene as electron acceptors in organic photovoltaics","volume":"8","author":"Umeyama","year":"2018","journal-title":"Rsc Adv."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1001","DOI":"10.1246\/cl.170306","article-title":"Enantiomerically Separated \u03b1-[70]PCBM for Organic Photovoltaics","volume":"46","author":"Umeyama","year":"2017","journal-title":"Chem. Lett."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1039\/C6SC02950G","article-title":"Regioisomer effects of [70]fullerene mono-adduct acceptors in bulk heterojunction polymer solar cells","volume":"8","author":"Umeyama","year":"2017","journal-title":"Chem. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"126602","DOI":"10.1103\/PhysRevLett.94.126602","article-title":"Space-Charge Limited Photocurrent","volume":"94","author":"Mihailetchi","year":"2005","journal-title":"Phys. Rev. Lett."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"899","DOI":"10.1016\/j.solmat.2010.11.016","article-title":"Biindene-C-60 adducts for the application as acceptor in polymer solar cells with higher open-circuit-voltage","volume":"95","author":"He","year":"2011","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1016\/j.solmat.2012.05.017","article-title":"Carbazole-containing fullerene derivatives for P3HT-based bulk-heterojunction solar cells","volume":"105","author":"Kim","year":"2012","journal-title":"Sol. Energy Mater. Sol. Cells"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"977","DOI":"10.1039\/C4TC02373K","article-title":"Isobenzofulvene-fullerene mono-adducts for organic photovoltaic applications","volume":"3","author":"Tseng","year":"2015","journal-title":"J. Mater. Chem. C"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.synthmet.2016.01.026","article-title":"Dihydrobenzofuran-C-60 bisadducts as electron acceptors in polymer solar cells: Effect of alkyl substituents","volume":"215","author":"Liu","year":"2016","journal-title":"Synth. Met."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"8550","DOI":"10.1039\/c2cc34078j","article-title":"Effects of dihydronaphthyl-based 60 fullerene bisadduct regioisomers on polymer solar cell performance","volume":"48","author":"Kitaura","year":"2012","journal-title":"Chem. Commun."},{"key":"ref_51","doi-asserted-by":"crossref","unstructured":"Nisic, F., Colombo, A., Dragonetti, C., Cominetti, A., Pellegrino, A., Perin, N., Po, R., and Tacca, A. (2014). Novel Terthiophene-Substituted Fullerene Derivatives as Easily Accessible Acceptor Molecules for Bulk-Heterojunction Polymer Solar Cells. Int. J. Photoenergy.","DOI":"10.1155\/2014\/373497"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1039\/B916597E","article-title":"Thienyl-substituted methanofullerene derivatives for organic photovoltaic cells","volume":"20","author":"Choi","year":"2010","journal-title":"J. Mater. Chem."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"17313","DOI":"10.1021\/am5058794","article-title":"Effects of Alkyl Chain Length and Substituent Pattern of Fullerene Bis-Adducts on Film Structures and Photovoltaic Properties of Bulk Heterojunction Solar Cells","volume":"6","author":"Tao","year":"2014","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/j.carbon.2015.04.011","article-title":"Efficiency enhancement from 60 fulleropyrrolidine-based polymer solar cells through N-substitution manipulation","volume":"92","author":"Liang","year":"2015","journal-title":"Carbon"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1246\/cl.141119","article-title":"Fulleropyrrolidine Derivatives with Benzophenone Moiety as Electron Acceptors in Thermally Stable Organic Photovoltaic Devices","volume":"44","author":"Yamane","year":"2015","journal-title":"Chem. Lett."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.optmat.2016.03.041","article-title":"Optical band gaps of organic semiconductor materials","volume":"58","author":"Costa","year":"2016","journal-title":"Opt. Mater."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1155\/2017\/1364152","article-title":"Bulk Heterojunction Organic Solar Cell Area-Dependent Parameter Fluctuation","volume":"2017","author":"Trindade","year":"2017","journal-title":"Int. J. Photoenergy"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1002\/1616-3028(200110)11:5<374::AID-ADFM374>3.0.CO;2-W","article-title":"Origin of the open circuit voltage of plastic solar cells","volume":"11","author":"Brabec","year":"2001","journal-title":"Adv. Funct. Mater."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"245207","DOI":"10.1103\/PhysRevB.82.245207","article-title":"Recombination in polymer-fullerene bulk heterojunction solar cells","volume":"82","author":"Cowan","year":"2010","journal-title":"Phys. Rev. B"},{"key":"ref_60","first-page":"93","article-title":"Morphology Analysis of Organic Solar Cells with Synchrotron Radiation Based Resonant Soft X-Ray Scattering","volume":"29","author":"Wu","year":"2017","journal-title":"Prog. Chem."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"10566","DOI":"10.1039\/c3cp50293g","article-title":"Practical applications of small-angle neutron scattering","volume":"15","author":"Hollamby","year":"2013","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"7692","DOI":"10.1002\/adma.201304187","article-title":"The Active Layer Morphology of Organic Solar Cells Probed with Grazing Incidence Scattering Techniques","volume":"26","year":"2014","journal-title":"Adv. Mater."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"1601674","DOI":"10.1002\/adma.201601674","article-title":"Conjugated-Polymer Blends for Organic Photovoltaics: Rational Control of Vertical Stratification for High Performance","volume":"29","author":"Yan","year":"2017","journal-title":"Adv. Mater."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"994","DOI":"10.1002\/polb.24002","article-title":"Phase behavior of blends of PCBM with amorphous polymers with different aromaticity","volume":"54","author":"Bernardo","year":"2016","journal-title":"J. Polym. Sci. Part B Polym. Phys."},{"key":"ref_65","doi-asserted-by":"crossref","unstructured":"Pyshkin, S.L., and John, M.B. (2013). Recent Progress in the Understanding and Manipulation of Morphology in Polymer: Fullerene Photovoltaic Cells. Optoelectronics-Advanced Materials and Devices, IntechOpen.","DOI":"10.5772\/3463"},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"15869","DOI":"10.1021\/ja305875u","article-title":"Polymer-Fullerene Miscibility: A Metric for Screening New Materials for High-Performance Organic Solar Cells","volume":"134","author":"Treat","year":"2012","journal-title":"J. Am. Chem. Soc."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"17570","DOI":"10.1039\/C7TA03505E","article-title":"Understanding the correlation and balance between the miscibility and optoelectronic properties of polymer\u2013fullerene solar cells","volume":"5","author":"Zhang","year":"2017","journal-title":"J. Mater. Chem. A"},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"5864","DOI":"10.1021\/acs.jpcc.6b11824","article-title":"Molecular Origin of Donor- and Acceptor-Rich Domain Formation in Bulk-Heterojunction Solar Cells with an Enhanced Charge Transport Efficiency","volume":"121","author":"Long","year":"2017","journal-title":"J. Phys. Chem. C"},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"485","DOI":"10.1039\/C1SC00674F","article-title":"Fullerene crystallisation as a key driver of charge separation in polymer\/fullerene bulk heterojunction solar cells","volume":"3","author":"Jamieson","year":"2012","journal-title":"Chem. Sci."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"1465","DOI":"10.1021\/jz300293q","article-title":"Insights from Transient Optoelectronic Analyses on the Open-Circuit Voltage of Organic Solar Cells","volume":"3","author":"Credgington","year":"2012","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"3865","DOI":"10.1021\/jz401971e","article-title":"Correlation between the Open Circuit Voltage and the Energetics of Organic Bulk Heterojunction Solar Cells","volume":"4","author":"Lange","year":"2013","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"10873","DOI":"10.1021\/jp110982m","article-title":"Influence of Fullerene Ordering on the Energy of the Charge-Transfer State and Open-Circuit Voltage in Polymer:Fullerene Solar Cells","volume":"115","author":"Piersimoni","year":"2011","journal-title":"J. Phys. Chem. C"},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"201","DOI":"10.1016\/j.sse.2012.07.018","article-title":"Carrier recombination flux in bulk heterojunction polymer:fullerene solar cells: Effect of energy disorder on ideality factor","volume":"79","year":"2013","journal-title":"Solid State Electron."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"075210","DOI":"10.1103\/PhysRevB.84.075210","article-title":"Relationship between energetic disorder and open-circuit voltage in bulk heterojunction organic solar cells","volume":"84","author":"Blakesley","year":"2011","journal-title":"Phys. Rev. B"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1002\/adfm.200801189","article-title":"Material Solubility-Photovoltaic Performance Relationship in the Design of Novel Fullerene Derivatives for Bulk Heterojunction Solar Cells","volume":"19","author":"Troshin","year":"2009","journal-title":"Adv. Funct. Mater."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"7313","DOI":"10.1039\/C4TC00502C","article-title":"Electron transport in crystalline PCBM-like fullerene derivatives: A comparative computational study","volume":"2","author":"Ide","year":"2014","journal-title":"J. Mater. Chem. C"},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1039\/C4MH00173G","article-title":"Distinguishing the influence of structural and energetic disorder on electron transport in fullerene multi-adducts","volume":"2","author":"Steiner","year":"2015","journal-title":"Mater. Horiz."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"3002","DOI":"10.1002\/adfm.200900459","article-title":"Electron Trapping in Higher Adduct Fullerene-Based Solar Cells","volume":"19","author":"Lenes","year":"2009","journal-title":"Adv. Funct. Mater."},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"10505","DOI":"10.1039\/C5OB01630D","article-title":"Regioselective synthesis of fullerene multiadducts via tether-directed 1,3-dipolar cycloaddition","volume":"13","author":"Zhang","year":"2015","journal-title":"Org. Biomol. Chem."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1002\/poc.3563","article-title":"Recent progress in the synthesis of regio-isomerically pure bis-adducts of empty and endohedral fullerenes","volume":"29","author":"Ceron","year":"2016","journal-title":"J. Phys. Org. Chem."},{"key":"ref_81","doi-asserted-by":"crossref","first-page":"9837","DOI":"10.1039\/C5CC02701B","article-title":"One-pot selective synthesis of a fullerene bisadduct for organic solar cell applications","volume":"51","author":"Zhang","year":"2015","journal-title":"Chem. Commun."},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"21338","DOI":"10.1021\/acsami.7b02155","article-title":"Interfacial Reaction of Fulleropyrrolidines Affecting Organic Photovoltaic Performance","volume":"9","author":"Karakawa","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"20889","DOI":"10.1039\/C4TA04857A","article-title":"N-phenyl 60 fulleropyrrolidines: Alternative acceptor materials to PC61BM for high performance organic photovoltaic cells","volume":"2","author":"Karakawa","year":"2014","journal-title":"J. Mater. Chem. A"},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"1769","DOI":"10.1016\/j.polymer.2014.02.034","article-title":"Synthesis and characterization of novel fulleropyrrolidine in P3HT blended bulk heterojunction solar cells","volume":"55","author":"Pitliya","year":"2014","journal-title":"Polymer"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/12\/24\/4100\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:40:27Z","timestamp":1760190027000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/12\/24\/4100"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,12,8]]},"references-count":84,"journal-issue":{"issue":"24","published-online":{"date-parts":[[2019,12]]}},"alternative-id":["ma12244100"],"URL":"https:\/\/doi.org\/10.3390\/ma12244100","relation":{},"ISSN":["1996-1944"],"issn-type":[{"type":"electronic","value":"1996-1944"}],"subject":[],"published":{"date-parts":[[2019,12,8]]}}}