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Her research activity is focused on the development of advanced conjugated organic and hybrid materials for smart applications in electronics, photonics, energy and sensing, with a particular interest in to green organic electronics, water soluble conjugated polyelectrolytes, nanomaterials, and sustainable materials, and processes for semiconducting organic materials.
Conjugated polymers with ionic pendant groups (CPEs) are receiving increasing attention as solution-processed interfacial materials for organic solar cells (OSCs). Various anionic CPEs have been successfully used, on top of ITO (Indium Tin Oxide) electrodes, as solution-processed anode interlayers (AILs) for conventional devices with direct geometry. However, the development of CPE AILs for OSC devices with inverted geometry is an important topic that still needs to be addressed. Here, we have designed three anionic CPEs bearing alkyl-potassium-sulfonate side chains. Their functional behavior as anode interlayers has been investigated in P3HT:PC61BM (poly(3-hexylthiophene): [6,6]-phenyl C61 butyric acid methyl ester) devices with an inverted geometry, using a hole collecting silver electrode evaporated on top. Our results reveal that to obtain effective anode modification, the CPEs’ conjugated backbone has to be tailored to grant self-doping and to have a good energy-level match with the photoactive layer. Furthermore, the sulfonate moieties not only ensure the solubility in polar orthogonal solvents, induce self-doping via a right choice of the conjugated backbone, but also play a role in the gaining of hole selectivity of the top silver electrode.
Elisa Lassi; Benedetta Squeo; Roberto Sorrentino; Guido Scavia; Simona Mrakic-Sposta; Maristella Gussoni; Barbara Vercelli; Francesco Galeotti; Mariacecilia Pasini; Silvia Luzzati. Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells. Molecules 2021, 26, 763 .
AMA StyleElisa Lassi, Benedetta Squeo, Roberto Sorrentino, Guido Scavia, Simona Mrakic-Sposta, Maristella Gussoni, Barbara Vercelli, Francesco Galeotti, Mariacecilia Pasini, Silvia Luzzati. Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells. Molecules. 2021; 26 (3):763.
Chicago/Turabian StyleElisa Lassi; Benedetta Squeo; Roberto Sorrentino; Guido Scavia; Simona Mrakic-Sposta; Maristella Gussoni; Barbara Vercelli; Francesco Galeotti; Mariacecilia Pasini; Silvia Luzzati. 2021. "Sulfonate-Conjugated Polyelectrolytes as Anode Interfacial Layers in Inverted Organic Solar Cells." Molecules 26, no. 3: 763.
The 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based molecules have emerged as interesting material for optoelectronic applications. The facile structural modification of BODIPY core provides an opportunity to fine-tune its photophysical and optoelectronic properties thanks to the presence of eight reactive sites which allows for the developing of a large number of functionalized derivatives for various applications. This review will focus on BODIPY application as solid-state active material in solar cells and in photonic devices. It has been divided into two sections dedicated to the two different applications. This review provides a concise and precise description of the experimental results, their interpretation as well as the conclusions that can be drawn. The main current research outcomes are summarized to guide the readers towards the full exploitation of the use of this material in optoelectronic applications.
Benedetta Maria Squeo; Lucia Ganzer; Tersilla Virgili; Mariacecilia Pasini. BODIPY-Based Molecules, A Platform for Photonic and Solar Cells. Molecules 2020, 26, 153 .
AMA StyleBenedetta Maria Squeo, Lucia Ganzer, Tersilla Virgili, Mariacecilia Pasini. BODIPY-Based Molecules, A Platform for Photonic and Solar Cells. Molecules. 2020; 26 (1):153.
Chicago/Turabian StyleBenedetta Maria Squeo; Lucia Ganzer; Tersilla Virgili; Mariacecilia Pasini. 2020. "BODIPY-Based Molecules, A Platform for Photonic and Solar Cells." Molecules 26, no. 1: 153.
Over the past 10 years, carbon dots (CDs) synthesized from renewable raw materials have received considerable attention in several fields for their unique photoluminescent properties. Moreover, the synthesis of CDs fully responds to the principles of circular chemistry and the concept of safe-by-design. This review will focus on the different strategies for incorporation of CDs in organic light-emitting devices (OLEDs) and on the study of the impact of CDs properties on OLED performance. The main current research outcomes and highlights are summarized to guide users towards full exploitation of these materials in optoelectronic applications.
Paola Lagonegro; Umberto Giovanella; Mariacecilia Pasini. Carbon Dots as a Sustainable New Platform for Organic Light Emitting Diode. Coatings 2020, 11, 5 .
AMA StylePaola Lagonegro, Umberto Giovanella, Mariacecilia Pasini. Carbon Dots as a Sustainable New Platform for Organic Light Emitting Diode. Coatings. 2020; 11 (1):5.
Chicago/Turabian StylePaola Lagonegro; Umberto Giovanella; Mariacecilia Pasini. 2020. "Carbon Dots as a Sustainable New Platform for Organic Light Emitting Diode." Coatings 11, no. 1: 5.
In the last 10 years, carbon dots (CDs) synthesized from renewable organic resources have been gathered a considerable amount of attention in different fields for their peculiar photoluminescent properties. Moreover, the synthesis of CDs fully responds to the principles of the circular chemistry and the concept of safe-by-design. This review will focus on the different strategies for the incorporation of CDs in organic light-emitting devices (OLEDs) and on the study of the impact of CDs properties on the OLEDs performance. The main current research outcomes and highlights are summarized to guide users towards the fully exploitation of use these materials in optoelectronic applications.
Paola Lagonegro; Umberto Giovanella; Mariacecilia Pasini. Carbon Dots as A Sustainable New Platform for Organic Light Emitting Diode. 2020, 1 .
AMA StylePaola Lagonegro, Umberto Giovanella, Mariacecilia Pasini. Carbon Dots as A Sustainable New Platform for Organic Light Emitting Diode. . 2020; ():1.
Chicago/Turabian StylePaola Lagonegro; Umberto Giovanella; Mariacecilia Pasini. 2020. "Carbon Dots as A Sustainable New Platform for Organic Light Emitting Diode." , no. : 1.
In the last years, interfacial engineering has played a critical role in promoting the performance of optoelectronic devices as organic solar cells (OSC) and organic light-emitting diodes (OLEDs) since interfacial layers help to form an ohmic contact between the electrodes and the active layers, which is of great importance for charge collection/injection. Conjugated polyelectrolytes (CPEs), which are conjugated polymers bearing side-chain ionic functionalities such as anionic, cationic, or zwitterionic groups, have emerged as a new class of interfacial materials in thin film-based electronic devices thanks to their ability to reduce the barrier between electrode and active layer. In view of this, we designed and synthesized two novel low bandgap anionic copolymers with different anionic pendant groups and different conjugated backbones to obtain hole-transporting layer (HTL) materials as an alternative to commonly used poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate). The functional behavior of these copolymers as anode modifiers is herein preliminarily investigated in an OLED prototype.
Benedetta Maria Squeo; Wojciech Mróz; Umberto Giovanella; Mariacecilia Pasini. Anionic Low Band Gap-Conjugated Polyelectrolytes as Hole-Transporting Layer in Optoelectronics Devices. Chemistry Proceedings 2020, 3, 18 .
AMA StyleBenedetta Maria Squeo, Wojciech Mróz, Umberto Giovanella, Mariacecilia Pasini. Anionic Low Band Gap-Conjugated Polyelectrolytes as Hole-Transporting Layer in Optoelectronics Devices. Chemistry Proceedings. 2020; 3 (1):18.
Chicago/Turabian StyleBenedetta Maria Squeo; Wojciech Mróz; Umberto Giovanella; Mariacecilia Pasini. 2020. "Anionic Low Band Gap-Conjugated Polyelectrolytes as Hole-Transporting Layer in Optoelectronics Devices." Chemistry Proceedings 3, no. 1: 18.
Paola Lagonegro; Christian Martella; Benedetta M. Squeo; Francesco Carulli; Guido Scavia; Alessio Lamperti; Francesco Galeotti; Benoit Dubertret; Mariacecilia Pasini; Sergio Brovelli; Alessandro Molle; Umberto Giovanella. Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS. ACS Applied Electronic Materials 2020, 2, 1186 -1192.
AMA StylePaola Lagonegro, Christian Martella, Benedetta M. Squeo, Francesco Carulli, Guido Scavia, Alessio Lamperti, Francesco Galeotti, Benoit Dubertret, Mariacecilia Pasini, Sergio Brovelli, Alessandro Molle, Umberto Giovanella. Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS. ACS Applied Electronic Materials. 2020; 2 (5):1186-1192.
Chicago/Turabian StylePaola Lagonegro; Christian Martella; Benedetta M. Squeo; Francesco Carulli; Guido Scavia; Alessio Lamperti; Francesco Galeotti; Benoit Dubertret; Mariacecilia Pasini; Sergio Brovelli; Alessandro Molle; Umberto Giovanella. 2020. "Prolonged Lifetime in Nanocrystal Light-Emitting Diodes Incorporating MoS2-Based Conjugated Polyelectrolyte Interfacial Layer as an Alternative to PEDOT:PSS." ACS Applied Electronic Materials 2, no. 5: 1186-1192.
A major problem of current biomedical implants is due to bacterial colonization and subsequent biofilm formation, which seriously affects their functioning and can lead to serious post-surgical complications. Intensive efforts have been directed towards the development of novel technologies that can prevent bacterial colonization while requiring minimal antibiotics doses. To this end, biocompatible materials with intrinsic antifouling capabilities are in high demand. Silk fibroin, widely employed in biotechnology, represents an interesting candidate. Here, we employ a soft-lithography approach to realize micro- and nano-structured silk fibroin substrates, with different geometries. We show that patterned silk film substrates support mammal cells (HEK-293) adhesion and proliferation, and at the same time they intrinsically display remarkable antifouling properties. We employ Escherichia coli as representative gram-negative bacteria and we observe a up to 66% decrease in the number of bacteria that adhere to patterned silk surfaces as compared to control, flat silk samples. The mechanism leading to the inhibition of biofilm formation critically depends on the microstructures geometry, involving both a steric and a hydrophobic effect. We also couple silk fibroin patterned films to a biocompatible, optically-responsive organic semiconductor, and we verify that the antifouling properties are very well preserved. The technology described here is of interest for the next-generation of biomedical implants, involving the use of materials with enhanced antibacterial capability, easily processable, highly biocompatible and promptly available for coupling with photoimaging and photodetection techniques.
Gabriele Tullii; Stefano Donini; Caterina Bossio; Francesco Lodola; Mariacecilia Pasini; Emilio Parisini; Francesco Galeotti; Maria Rosa Antognazza. Micro- and Nanopatterned Silk Substrates for Antifouling Applications. ACS Applied Materials & Interfaces 2020, 12, 5437 -5446.
AMA StyleGabriele Tullii, Stefano Donini, Caterina Bossio, Francesco Lodola, Mariacecilia Pasini, Emilio Parisini, Francesco Galeotti, Maria Rosa Antognazza. Micro- and Nanopatterned Silk Substrates for Antifouling Applications. ACS Applied Materials & Interfaces. 2020; 12 (5):5437-5446.
Chicago/Turabian StyleGabriele Tullii; Stefano Donini; Caterina Bossio; Francesco Lodola; Mariacecilia Pasini; Emilio Parisini; Francesco Galeotti; Maria Rosa Antognazza. 2020. "Micro- and Nanopatterned Silk Substrates for Antifouling Applications." ACS Applied Materials & Interfaces 12, no. 5: 5437-5446.
The development of high performance optically pumped organic lasers operating in the deep blue still remains a big challenge. In this paper, we have investigated the photophysics and the optical gain characteristics of a novel fluorene oligomer functionalized by four triphenylamine (TPA) groups. By ultrafast spectroscopy we found a large gain spectral region from 420 to 500 nm with a maximum gain cross-section of 1.5 × 10-16 cm2 which makes this molecule a good candidate for photonic applications. Amplified Spontaneous Emission measurements (ASE) under 150 fs and 3 ns pump pulses have revealed a narrow emission at 450 nm with a threshold of 5.5 μJcm-2 and 21 μJcm-2 respectively. Our results evidence that this new fluorene molecule is an interesting material for photonic applications, indeed the inclusion of TPA as a lateral substituent leads to a high gain and consequently to a low threshold blue organic ASE.
Tersilla Virgili; Marco Anni; Maria Luisa De Giorgi; Rocio Borrego Varillas; Benedetta M. Squeo; Mariacecilia Pasini. Deep Blue Light Amplification from a Novel Triphenylamine Functionalized Fluorene Thin Film. Molecules 2019, 25, 79 .
AMA StyleTersilla Virgili, Marco Anni, Maria Luisa De Giorgi, Rocio Borrego Varillas, Benedetta M. Squeo, Mariacecilia Pasini. Deep Blue Light Amplification from a Novel Triphenylamine Functionalized Fluorene Thin Film. Molecules. 2019; 25 (1):79.
Chicago/Turabian StyleTersilla Virgili; Marco Anni; Maria Luisa De Giorgi; Rocio Borrego Varillas; Benedetta M. Squeo; Mariacecilia Pasini. 2019. "Deep Blue Light Amplification from a Novel Triphenylamine Functionalized Fluorene Thin Film." Molecules 25, no. 1: 79.
The rapid appearance of organic optoelectronics as a promising alternative to conventional optoelectronics has been largely achieved through the design and development of new conjugated systems. The 4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene (BODIPY)-based materials have recently emerged as platforms for many types of applications such as sensors, organic thin-film transistors and organic photovoltaics; however, their application as active materials in organic light-emitting diodes (OLEDs) has only been poorly explored. This review article provides an overview of the most important developments in the structural design and synthesis of BODIPY-based organic semiconductors for application in OLED devices. The results summarised and discussed here include the most relevant results starting from the first application of BODIPY-based materials in OLEDs in 2002 up to the recent discoveries as near-IR emitters also promoted by aggregation-induced emission (AIE). Therefore, this review should inspire new research for future developments of BODIPY-based materials, in particular as ‘metal-free’ infrared emitters. Abbreviations: ACQ: aggregation caused quenching; AIE: aggregation induced emission; Alq3: aluminium tris(8-hydroxyquinoline); BCP: 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline); BDP-PPV: poly(bis(3″,7″-dimethyloctyloxy))p-phenylene vinylene; BF3OEt2: boron trifluoride diethyletherate; BPhen: bathophenanthroline; CBP: 4,40-bis[N-carbazolyl]-2,20-biphenyl; CIE: Commission Internationale de l’Eclairage; DDQ: dichloro-dicyano-quinone; EL: electroluminescence; F8BT: poly(9,9-dioctylfluorene-alt-benzothiadiazole); ITO: indium tin oxide; LEC: light-emitting electrochemical cell; m-MTDATA: 4,4ʹ,4ʹ’-tris[phenyl(m-tolyl)amino]triphenylamine; NPB: N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)benzidine; NPD: N,N’-di(1-naphtyl)-N,N’-diphenylbenzidine; OLED: organic light-emitting diode; OPV: organic photovoltaic; OXD-7: 2,2′-(1,3-phenylene)-bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole; PBD: 2-(4-biphenylyl)-5(4tert-butyl-phenyl)-1,3,4-oxadiazole; PEDOT: poly(3,4-ethylenedioxythiophene); PLED: polymeric light-emitting diodes; PMMA: polymethylmetacrilate; PPT: 2,8-bis(diphenylphosphoryl)dibenzo[b,d]thiophene; PSS: polystyrene sulphonic sodium salt; PVK: poly(9-N-vinylcarbazole); TPBi: 2,2ʹ,2”-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole); TPE: tetraphenylethylene; WOLED: white organic light-emitting diode; 3-TPyMB: tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane
Benedetta Maria Squeo; Mariacecilia Pasini. BODIPY platform: a tunable tool for green to NIR OLEDs. Supramolecular Chemistry 2019, 32, 56 -70.
AMA StyleBenedetta Maria Squeo, Mariacecilia Pasini. BODIPY platform: a tunable tool for green to NIR OLEDs. Supramolecular Chemistry. 2019; 32 (1):56-70.
Chicago/Turabian StyleBenedetta Maria Squeo; Mariacecilia Pasini. 2019. "BODIPY platform: a tunable tool for green to NIR OLEDs." Supramolecular Chemistry 32, no. 1: 56-70.
Multilayers of sulphur-based anchoring group linkers and CdSe nanocrystals (NCs) were realized on ITO substrate via layer-by-layer alternation. The materials were investigated by UV-vis and FTIR spectroscopy, photoluminescence and photoconductivity. We found that the change of NCs packing during the multilayers build-up produces a progressive increase of exciton delocalization. In fact during multilayer deposition the NCs first excitonic peak shifts progressively towards longer wavelengths. We found a linear relation between the optical bang gap shift ("" E_gn) and the inverse of number of CdSe-NCs layers ( n ) for n > 2, in particular the decrease of its value for the infinite multilayer from the one of the solution (2.10 eV) goes from 18 meV for the 1,2-ethylene-bis(dithiocarbamate) (EDTC) linker to 66 meV for sulphide dianions, corresponding to an apparent increase of the exciton radius of 0.20 nm and 0.85nm respectively.
Barbara Vercelli; Tersilla Virgili; Mariacecilia Pasini; Anna Berlin; Gianni Zotti. Multilayers of Carbodithioate and Sulfide-Linked CdSe Nanocrystals: Progressive Increase of Exciton Delocalization. The Journal of Physical Chemistry C 2019, 123, 23159 -23166.
AMA StyleBarbara Vercelli, Tersilla Virgili, Mariacecilia Pasini, Anna Berlin, Gianni Zotti. Multilayers of Carbodithioate and Sulfide-Linked CdSe Nanocrystals: Progressive Increase of Exciton Delocalization. The Journal of Physical Chemistry C. 2019; 123 (37):23159-23166.
Chicago/Turabian StyleBarbara Vercelli; Tersilla Virgili; Mariacecilia Pasini; Anna Berlin; Gianni Zotti. 2019. "Multilayers of Carbodithioate and Sulfide-Linked CdSe Nanocrystals: Progressive Increase of Exciton Delocalization." The Journal of Physical Chemistry C 123, no. 37: 23159-23166.
Hybrid interfaces between living cells and nano/microstructured scaffolds have huge application potential in biotechnology, spanning from regenerative medicine and stem cell therapies to localized drug delivery and from biosensing and tissue engineering to neural computing. However, 3D architectures based on semiconducting polymers, endowed with responsivity to visible light, have never been considered. Here, we apply for the first time a push-coating technique to realize high aspect ratio polymeric pillars, based on polythiophene, showing optimal biocompatibility and allowing for the realization of soft, 3D cell cultures of both primary neurons and cell line models. HEK-293 cells cultured on top of polymer pillars display a remarkable change in the cell morphology and a sizable enhancement of the membrane capacitance due to the cell membrane thinning in correspondence to the pillars' top surface, without negatively affecting cell proliferation. Electrophysiology properties and synapse number of primary neurons are also very well preserved. In perspective, high aspect ratio semiconducting polymer pillars may find interesting applications as soft, photoactive elements for cell activity sensing and modulation.
Gabriele Tullii; Federica Giona; Francesco Lodola; Silvio Bonfadini; Caterina Bossio; Simone Varo; Andrea Desii; Luigino Criante; Carlo Sala; Mariacecilia Pasini; Chiara Verpelli; Francesco Galeotti; Maria Rosa Antognazza. High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures. ACS Applied Materials & Interfaces 2019, 11, 28125 -28137.
AMA StyleGabriele Tullii, Federica Giona, Francesco Lodola, Silvio Bonfadini, Caterina Bossio, Simone Varo, Andrea Desii, Luigino Criante, Carlo Sala, Mariacecilia Pasini, Chiara Verpelli, Francesco Galeotti, Maria Rosa Antognazza. High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures. ACS Applied Materials & Interfaces. 2019; 11 (31):28125-28137.
Chicago/Turabian StyleGabriele Tullii; Federica Giona; Francesco Lodola; Silvio Bonfadini; Caterina Bossio; Simone Varo; Andrea Desii; Luigino Criante; Carlo Sala; Mariacecilia Pasini; Chiara Verpelli; Francesco Galeotti; Maria Rosa Antognazza. 2019. "High-Aspect-Ratio Semiconducting Polymer Pillars for 3D Cell Cultures." ACS Applied Materials & Interfaces 11, no. 31: 28125-28137.
Two branched oligophenylenethynylenes with phenylene or biphenylene moieties as inter‐nodal fragments are synthesized by the Sonogashira reaction for optoelectronic applications. The branching of polyphenylenethynylenes influences the electro‐optical properties, but cannot be precisely controlled, while its determination is often hardly addressed. The optical investigation, supported by nuclear magnetic resonance (NMR) studies, of oligophenylenethynylenes and the properly synthesized model compounds is performed to get insights on the branching and related effect on the material performance. The proposed branched oligophenylenethynylenes are good ultraviolet emitters in solution, while in solid‐state aggregation phenomena strongly affect emission properties. However, the interactions between π‐electrons on phenylene and ethynylene of neighboring molecules in films enhance intermolecular charge transport (hole mobility = 3.2 × 10−3 cm2 V−1s−1) making them optimal candidates as hole transport materials in optoelectronic devices. The insertion of the oligophenylenethynylene film as a hole transporting layer in multilayered solution processes blue, green, and red electroluminescent diodes, enhances OLEDs electro‐optical properties.
Wojciech Mroz; Aleksey I. Kovalev; Marina A. Babushkina‐Lebedeva; Natalia S. Kushakova; Barbara Vercelli; Benedetta Maria Squeo; Chiara Botta; Mariacecilia Pasini; Silvia Destri; Umberto Giovanella; Irina A. Khotina. Branched Oligophenylenes with Phenylene–Ethynylene Fragments as Anode Interfacial Layer for Solution Processed Optoelectronics. Macromolecular Chemistry and Physics 2019, 1 .
AMA StyleWojciech Mroz, Aleksey I. Kovalev, Marina A. Babushkina‐Lebedeva, Natalia S. Kushakova, Barbara Vercelli, Benedetta Maria Squeo, Chiara Botta, Mariacecilia Pasini, Silvia Destri, Umberto Giovanella, Irina A. Khotina. Branched Oligophenylenes with Phenylene–Ethynylene Fragments as Anode Interfacial Layer for Solution Processed Optoelectronics. Macromolecular Chemistry and Physics. 2019; ():1.
Chicago/Turabian StyleWojciech Mroz; Aleksey I. Kovalev; Marina A. Babushkina‐Lebedeva; Natalia S. Kushakova; Barbara Vercelli; Benedetta Maria Squeo; Chiara Botta; Mariacecilia Pasini; Silvia Destri; Umberto Giovanella; Irina A. Khotina. 2019. "Branched Oligophenylenes with Phenylene–Ethynylene Fragments as Anode Interfacial Layer for Solution Processed Optoelectronics." Macromolecular Chemistry and Physics , no. : 1.
Polar semiconducting polymers based on a conjugated polymer backbone endowed with chemically anchored polar groups on the side chains have proved to be particularly interesting as optimization layer at organic/cathode interface in optoelectronic devices. In particular, the pendant phosphonate groups impart water-alcohol solubility allowing easy solution processing, and improve electron injection thanks to both a favorable interfacial dipole of phosphonate groups and an intense coordination interaction between the phosphonate groups and Al cathode. In this work we synthesize alternating fluorene-benzothiadiazole copolymers by proposing a post-polymerization reaction to insert the phosphonate groups. Thanks to this approach it is possible to use standard Suzuki coupling conditions, simplifying the process of synthesis, purification and characterization. The polymer Poly[9,9-bis(6′-diethoxylphosphorylhexyl)-alt-benzothiadiazole] (P2), is tested in conventional organic solar cells as cathode interfacial layers showing, with respect to the control device, an increasing of all the photovoltaic parameters, with a final power conversion efficiency that reaches 5.35% starting from 4.6%. The same trend is observed for multilayered polymer light-emitting diodes with an external quantum efficiency of the P2-based PLED enhanced of 1.5 times with respect to the basic devices with bare Al cathode, and negligible roll-off efficiency. The synergic effects of energy gap modulation and of polar phosphonated pendant functionalities of P2 are compared with the corresponding fluorene-based polar homopolymer. Our results show that, not only a proper selection of side functionalities, but also the tailoring of the energy gap of cathode interfacial materials (CIMs) is a possible effective strategy to engineer cathode of different optoelectronic devices and enhance their performance.
Benedetta Maria Squeo; Francesco Carulli; Elisa Lassi; Francesco Galeotti; Umberto Giovanella; Silvia Luzzati; Mariacecilia Pasini. Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices. Pure and Applied Chemistry 2019, 91, 477 -488.
AMA StyleBenedetta Maria Squeo, Francesco Carulli, Elisa Lassi, Francesco Galeotti, Umberto Giovanella, Silvia Luzzati, Mariacecilia Pasini. Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices. Pure and Applied Chemistry. 2019; 91 (3):477-488.
Chicago/Turabian StyleBenedetta Maria Squeo; Francesco Carulli; Elisa Lassi; Francesco Galeotti; Umberto Giovanella; Silvia Luzzati; Mariacecilia Pasini. 2019. "Benzothiadiazole-based conjugated polyelectrolytes for interfacial engineering in optoelectronic devices." Pure and Applied Chemistry 91, no. 3: 477-488.
In this work a novel combination of side chain functionalities, alkyl-phosphonate (EP) and alkyl-ammonium bromide (NBr) groups, on a polyfluorene backbone (PF-NBr-EP) was studied as cathode interfacial material (CIM) in polymer-based solar cells. The devices were made with a conventional geometry, with PTB7:PC71 BM as active layer and aluminum as metal electrode. The CIM showed good solubility in ethanol and film forming ability onto the active layer so that its deposition could be finely tuned. The interface engineering imparted by this CIM was assessed and discussed through kelvin probe force microscopy (KPFM), impedance spectroscopy, charge recombination and electron transport characterizations. To discriminate between the interfacial modifications imparted by the interlayer and its solvent, we included in this study a surface ethanol treated device. In the optimized conditions an average power conversion efficiency of 7.24% was obtained, which is about 60% higher when compared to devices made with bare Al and 26% when compared to devices made with a standard calcium/aluminum cathode. Besides performances, some insights about the devices shelf life stability are also presented. A good persistency through aging was found for the cathode interfacial engineering capabilities of PF-NBr-EP.
Francesco Carulli; Guido Scavia; Elisa Lassi; Mariacecilia Pasini; Francesco Galeotti; Sergio Brovelli; Umberto Giovanella; Silvia Luzzati. A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells. Journal of Colloid and Interface Science 2018, 538, 611 -619.
AMA StyleFrancesco Carulli, Guido Scavia, Elisa Lassi, Mariacecilia Pasini, Francesco Galeotti, Sergio Brovelli, Umberto Giovanella, Silvia Luzzati. A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells. Journal of Colloid and Interface Science. 2018; 538 ():611-619.
Chicago/Turabian StyleFrancesco Carulli; Guido Scavia; Elisa Lassi; Mariacecilia Pasini; Francesco Galeotti; Sergio Brovelli; Umberto Giovanella; Silvia Luzzati. 2018. "A bifunctional conjugated polyelectrolyte for the interfacial engineering of polymer solar cells." Journal of Colloid and Interface Science 538, no. : 611-619.
Organic light-emitting transistors (OLETs) show the fascinating combination of electrical switching characteristics and light generation capability. However, to ensure an effective device operation, efficient injection of charges into the emissive layer is required. The introduction of solution-processed conjugated polyelectrolytes (CPEs) films at the emissive layer/electrode interface represents a promising strategy to improve the electron-injection process by dipole formation. However, their use in optoelectronic devices involves also some limitations due to the ionic nature of CPEs. In this context, neutral conjugated polar polymers (CPPs) represent a valid alternative to CPEs since the conjugated backbones of CPPs are functionalized with polar non-ionic side groups, thus avoiding ion-dependent drawbacks. By introducing a layer of polyfluorene containing phosphonate groups (PF-EP) underneath the metal electrodes, we here demonstrate a substantial improvement of the electron injection properties into the OLET emissive layer and, accordingly, a more than twofold increased light power and a five-times-higher external quantum efficiency of p-type OLETs in comparison with reference devices without any interlayer. The great benefit of using a transparent glass substrate allowed to selectively investigate the morphological and photoluminescent characteristics of both CPE- and CPP-buried interlayers within complete OLETs by means of an optical scanning probe technique. This, together with a thorough optoelectronic characterization of the figures of merit of working light-emitting devices allowed to disclose the origin of the improved optical performance of CPP-based devices as well as the operation mechanisms of the investigated interlayer in the corresponding OLETs.
Mario Prosa; Emilia Benvenuti; Mariacecilia Pasini; Umberto Giovanella; Margherita Bolognesi; Lorenzo Meazza; Francesco Galeotti; Michele Muccini; Stefano Toffanin. Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers. ACS Applied Materials & Interfaces 2018, 10, 25580 -25588.
AMA StyleMario Prosa, Emilia Benvenuti, Mariacecilia Pasini, Umberto Giovanella, Margherita Bolognesi, Lorenzo Meazza, Francesco Galeotti, Michele Muccini, Stefano Toffanin. Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers. ACS Applied Materials & Interfaces. 2018; 10 (30):25580-25588.
Chicago/Turabian StyleMario Prosa; Emilia Benvenuti; Mariacecilia Pasini; Umberto Giovanella; Margherita Bolognesi; Lorenzo Meazza; Francesco Galeotti; Michele Muccini; Stefano Toffanin. 2018. "Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers." ACS Applied Materials & Interfaces 10, no. 30: 25580-25588.
Colloidal nanoplatelets (NPLs), owning to their efficient, narrowband luminescence, are considered promising candidates for solution-processable light-emitting diodes (LEDs) with ultra-high color purity. To date, however, the record efficiencies of NPLs-LED are significantly lower than more investigated devices based on spherical nanocrystals. This is particularly true for red-emitting NPL-LEDs, whose best reported EQE is limited to 0.63% (EQE=5% for green NPL-LEDs). Here, we address this issue by introducing a charge regulating layer of a polar/polyelectrolytic polymer specifically engineered with complementary trimethylammonium and phosphonate functionalities that provide high solubility in orthogonal polar media with respect to the NPL active layer, compatibility with the metal cathode and the ability to control electron injection through the formation of a polarized interface under bias. Through this synergic approach, we achieve EQE=5.73% at 658 nm (color saturation 98%) in fully solution-processed LEDs. Remarkably, exposure to air increases the EQE to 8.39%, exceeding the best reports of red NPL-LED by over one order of magnitude and setting a new global record for quantum dot LEDs of any color incorporating solution-deposited organic interlayers. Considering the emission quantum yield of the NPLs (40±5%), this value corresponds to a nearly unity internal quantum efficiency. Notably, our devices show exceptional operational stability for over 5 hours of continuous drive in air with no encapsulation, thus confirming the potential of NPLs for efficient, high-stability, saturated LEDs.
Umberto Giovanella; Mariacecilia Pasini; Monica Lorenzon; Francesco Galeotti; Claudio Lucchi; Francesco Meinardi; Silvia Luzzati; Benoit Dubertret; Sergio Brovelli. Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air. Nano Letters 2018, 18, 3441 -3448.
AMA StyleUmberto Giovanella, Mariacecilia Pasini, Monica Lorenzon, Francesco Galeotti, Claudio Lucchi, Francesco Meinardi, Silvia Luzzati, Benoit Dubertret, Sergio Brovelli. Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air. Nano Letters. 2018; 18 (6):3441-3448.
Chicago/Turabian StyleUmberto Giovanella; Mariacecilia Pasini; Monica Lorenzon; Francesco Galeotti; Claudio Lucchi; Francesco Meinardi; Silvia Luzzati; Benoit Dubertret; Sergio Brovelli. 2018. "Efficient Solution-Processed Nanoplatelet-Based Light-Emitting Diodes with High Operational Stability in Air." Nano Letters 18, no. 6: 3441-3448.
Interchain interactions can play a positive role in reaching amplified spontaneous emission in an interesting core–polymer system where the donor (side chains) and the acceptor (core) are chemically linked together. Different degree of interchain interactions modifies the photophysical characteristics of the polymer. By means of transient absorption spectroscopy we show that the stimulated emission from the core decreases passing from solid state to concentrated solution and it is almost absent in the diluted solution. The conformational rearrangements of the core–polymer chain in solution limits the efficiency of the intrachain Förster energy transfer mechanism. The free chain rotations decrease the exciton hopping along the conjugated chains, the ratio between donor and acceptor moieties in the polymer, and change the relative orientation of the transition dipoles of the donor and acceptor causing a strong decrease of energy transfer efficiency and subsequently of the gain. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 965–969
Serena Bolis; Mariacecilia Pasini; Tersilla Virgili. Ultrafast study of inter- and intrachain energy transfer in a core-polymer. Journal of Polymer Science Part B: Polymer Physics 2018, 56, 965 -969.
AMA StyleSerena Bolis, Mariacecilia Pasini, Tersilla Virgili. Ultrafast study of inter- and intrachain energy transfer in a core-polymer. Journal of Polymer Science Part B: Polymer Physics. 2018; 56 (13):965-969.
Chicago/Turabian StyleSerena Bolis; Mariacecilia Pasini; Tersilla Virgili. 2018. "Ultrafast study of inter- and intrachain energy transfer in a core-polymer." Journal of Polymer Science Part B: Polymer Physics 56, no. 13: 965-969.
Interfacial engineering provides an important tool for optimizing the performances of optoelectronic devices. We show that poly[(2,7-(9,9′-dioctyl)fluorene)-alt-(2,7-(9,9′-bis(5″-trimethylammonium bromide)pentyl)fluorene)])], an alcohol-soluble π-conjugated polymer based on polyfluorene backbone and ammonium groups on the alkyl side chains, is capable of modifying the interface between the organic layer and the metal cathode in both organic solar cells and light-emitting diodes based on commercial materials and conventional architectures, improving their performances. The introduction of the cathode interlayer enhances the efficiency of a red-emitting phosphorescent OLED by 15% and decreases its turn-on voltage. The same polymer improves the power conversion efficiency of a PTB7/PC71BM solar cell by 55% and shows a beneficial effect in terms of device stability.
Francesco Carulli; Wojciech Mroz; Elisa Lassi; Cristina Sandionigi; Benedetta Maria Squeo; Lorenzo Meazza; Guido Scavia; Silvia Luzzati; Mariacecilia Pasini; Umberto Giovanella; Francesco Galeotti. Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices. Chemical Papers 2018, 72, 1753 -1759.
AMA StyleFrancesco Carulli, Wojciech Mroz, Elisa Lassi, Cristina Sandionigi, Benedetta Maria Squeo, Lorenzo Meazza, Guido Scavia, Silvia Luzzati, Mariacecilia Pasini, Umberto Giovanella, Francesco Galeotti. Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices. Chemical Papers. 2018; 72 (7):1753-1759.
Chicago/Turabian StyleFrancesco Carulli; Wojciech Mroz; Elisa Lassi; Cristina Sandionigi; Benedetta Maria Squeo; Lorenzo Meazza; Guido Scavia; Silvia Luzzati; Mariacecilia Pasini; Umberto Giovanella; Francesco Galeotti. 2018. "Effect of the introduction of an alcohol-soluble conjugated polyelectrolyte as cathode interlayer in solution-processed organic light-emitting diodes and photovoltaic devices." Chemical Papers 72, no. 7: 1753-1759.
Push-coating is a green and extremely low-cost process in which only few microliters of conjugated polymer solutions are used to produce thin films using capillary forces. Here, we adapt this fabrication technique to replicate self-assembled nanoporous structures on green and red light-emitting conjugated polymer thin films. These films display ring-like photoluminescence and are successfully integrated into polymer light-emitting devices as emitting layers. At low applied voltages, the green-emitting devices exhibit electroluminescence from hexagonally arranged nanopixel arrays resulting from a stronger electric field in the thinner areas inside the pores. By gradually increasing the voltage up to 10V, the emission extends to the areas around the pores. At voltages higher than 10V, a non-reversible nanopixel to nanoring-like switching of the electroluminescence can be observed. After filling the pores with a second blue-emitting conjugated polymer, voltage-dependent reversible color tuning of the electroluminescence is achieved in the nanostructured light-emitting bilayers.
Varun Vohra; Francesco Galeotti; Umberto Giovanella; Wojciech Mróz; Mariacecilia Pasini; Chiara Botta. Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique. ACS Applied Materials & Interfaces 2018, 10, 11794 -11800.
AMA StyleVarun Vohra, Francesco Galeotti, Umberto Giovanella, Wojciech Mróz, Mariacecilia Pasini, Chiara Botta. Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique. ACS Applied Materials & Interfaces. 2018; 10 (14):11794-11800.
Chicago/Turabian StyleVarun Vohra; Francesco Galeotti; Umberto Giovanella; Wojciech Mróz; Mariacecilia Pasini; Chiara Botta. 2018. "Nanostructured Light-Emitting Polymer Thin Films and Devices Fabricated by the Environment-Friendly Push-Coating Technique." ACS Applied Materials & Interfaces 10, no. 14: 11794-11800.
Short-channel field-effect transistors (FETs) prepared from semiconducting single-walled carbon nanotube (s-SWNT) dispersions sorted with poly(2,5-dimethylidynenitrilo-3,4-didodecylthienylene) are demonstrated. Electrical analysis of the FETs shows no evidence of metallic tubes out of a total number of 646 SWNTs tested, implying an estimated purity of our semiconducting SWNT solution higher than 99.85%. These findings confirm the effectiveness of the polymer-wrapping technique in selecting semiconducting SWNTs, as well as the potential of sorted nanotubes for the fabrication of short channel FETs comprising from 1 to up to 15 nanotubes without inter-nanotube junctions.
Vladimir Derenskyi; Widianta Gomulya; Jia Gao; Satria Zulkarnaen Bisri; Mariacecilia Pasini; Yueh-Lin Loo; Maria Antonietta Loi. Semiconducting SWNTs sorted by polymer wrapping: How pure are they? Applied Physics Letters 2018, 112, 072106 .
AMA StyleVladimir Derenskyi, Widianta Gomulya, Jia Gao, Satria Zulkarnaen Bisri, Mariacecilia Pasini, Yueh-Lin Loo, Maria Antonietta Loi. Semiconducting SWNTs sorted by polymer wrapping: How pure are they? Applied Physics Letters. 2018; 112 (7):072106.
Chicago/Turabian StyleVladimir Derenskyi; Widianta Gomulya; Jia Gao; Satria Zulkarnaen Bisri; Mariacecilia Pasini; Yueh-Lin Loo; Maria Antonietta Loi. 2018. "Semiconducting SWNTs sorted by polymer wrapping: How pure are they?" Applied Physics Letters 112, no. 7: 072106.