Nanocluster di metalli preparati mediante ablazione Laser in liquido

Bulk heterojunctions by boramers for plastic photovoltaics

Selecting speed-dependent pathways for a programmable nanoscale texture at wet interfaces

Engeneering 3D Nanoscale Order in Molecular thin films for organic photovoltaics

Monolayer and multilayer field-effect transistors based on a high-mobility n-type polymer: effect of the polymeric texture on charge transport

Nanoscale control in organic bulk heterojunctions of new set of materials for photovoltaic applications

3D nanoscale ordered architectures in thin films for organic electronics

Order in molecular thin films is of fundamental importance to gain and exploit a series of properties in nanotechnology. In this contest, engineering 2D supramolecular and molecular superstructures is of particular interest. They offer great possibilities for several applications whose achievement also allows for new theoretical approaches and nanoscale laws [1]. A natural extension of 2D nanopatterning concerns the attainment of a 3D nanoscale control in molecular films [2]. This question is complex to challenge and it is of ultimate importance in emerging fields like organic and hybrid photovoltaics, organic thin film transistors and sensors as well as plastic electronics. For example, th…

Controlling molecular packing for charge transport in organic thin film devices

Boramers for Photovoltaic Applications

Engineering 3D ordered molecular thin films by a nanoscale control

This perspective aims to report on experimental preparation and investigation tools for engineering molecular thin films with a three-dimensional (3D) nanoscale control that is of relevant interest for different emerging applications as well as for the development of calibration standards. Such thin films may be obtained by man-made methods, self-assembly or spatio-temporal self-organization and/or by the combination of these last approaches with external tools. Understanding the main features and the physical-chemistry underlying the related ordering phenomena is in due course and a theoretical framework is under development. In this respect it is of fundamental importance to achieve the a…

3D Order for Improved Organic Solar Cells Effiency

Eterogiunzioni bulk a base di polimeri di borani per celle fotovoltaiche flessibili

Assembling 3D Ordered Architectures in Thin Films for Organic Solar Cells

3D-ORDERED NANOSCALE HETEROJUNCTIONS IN MOLECULAR THIN FILMS FOR ORGANIC PHOTOVOLTAICS

ChemInform Abstract: Selecting Speed-Dependent Pathways for a Programmable Nanoscale Texture by Wet Interfaces

The realization of well-defined and ordered structures on the nanoscale is a main issue in nanoscience and nanotechnology, biotechnology and other related fields like plastic or organic electronics. Among the bottom-up approaches, to date, self-assembly (equilibrium aggregates) received a major attention. In spite of this, far from equilibrium conditions allow for the generation of a wider landscape of organized systems depending on the set of control parameters employed. Under an adaptation vision of the structures, here we report some case studies showing how it is possible to programme and control the nanoscale features of ordered super- or supra-aggregates at wet interfaces by modulatin…

Selecting speed-dependent pathways for a programmable nanoscale texture by wet interfaces

The realization of well-defined and ordered structures on the nanoscale is a main issue in nanoscience and nanotechnology, biotechnology and other related fields like plastic or organic electronics. Among the bottom-up approaches, to date, self-assembly (equilibrium aggregates) received a major attention. In spite of this, far from equilibrium conditions allow for the generation of a wider landscape of organized systems depending on the set of control parameters employed. Under an adaptation vision of the structures, here we report some case studies showing how it is possible to programme and control the nanoscale features of ordered super- or supra-aggregates at wet interfaces by modulatin…

Role of photoactive layer morphology in high fill factor all-polymer bulk heterojunction solar cells

We report on the realization of all-polymer solar cells based on blends of poly(3-hexylthiophene-2,5-diyl) (P3HT) as a donor and poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (P(NDI2OD-T2)) as an acceptor. High fill factors are demonstrated for the first time in this class of devices suggesting high dissociation efficiency for the bounded electron-hole pairs and balanced electron and hole mobility along the thin films. The use of the high-mobility n-type P(NDI2OD-T2) polymer enables us to overcome one of the problems limiting the efficiency of all-polymer solar cells, resulting in fill factors comparable with those reported for …

Organic Transistors: Supramolecular Order of Solution-Processed Perylenediimide Thin Films: High-Performance Small-Channel n-Type Organic Transistors (Adv. Funct. Mater. 23/2011)

Nano-structured molecular thin films for bio-sensing and plastic-electronics with improved efficiency/cost ratio

Supramolecular Order of Solution-Processed Perylenediimide Thin Films

N,N ′ -1 H ,1 H -perfl uorobutyl dicyanoperylenecarboxydiimide (PDIF-CN 2 ), a soluble and air stable n-type molecule, undergoes signifi cant reorganization upon thermal annealing after solution deposition on several substrates with different surface energies. Interestingly, this system exhibits an exceptional edge-on orientation regardless of the substrate chemistry. This preferential orientation is rationalized in terms of strong intermolecular interactions between the PDIF-CN 2 molecules. The presence of a pronounced π– π stacking is confi rmed by combining near-edge X-ray absorption fi ne structure spectroscopy (NEXAFS), dynamic scanning force microscopy (SFM) and surface energy measure…

From monolayer to multilayer N-channel polymeric field-effect transistors with precise conformational order

Monolayer field-effect transistors based on a high-mobility n-type polymer are demonstrated. The accurate control of the long-range order by Langmuir-Schafer (LS) deposition yields dense polymer packing exhibiting good injection properties, relevant current on/off ratio and carrier mobility in a staggered configuration. Layer-by-layer LS film transistors of increasing thickness are fabricated and their performance compared to those of spin-coated films.

Naphthalenediimide Polymers with Finely Tuned In-Chain π-Conjugation: Electronic Structure, Film Microstructure, and Charge Transport Properties

Naphthalenediimide-based random copolymers (PNDI-TVTx) with different π-conjugated dithienylvinylene (TVT) versus π-nonconjugated dithienylethane (TET) unit ratios (x = 100→0%) are investigated. The PNDI-TVTx-transistor electron/hole mobilities are affected differently, a result rationalized by molecular orbital topologies and energies, with hole mobility vanishing but electron mobility decreasing only by ≈2.5 times when going from x = 100% to 40%.

ORGANOBORON POLYMERS FOR HIGH-EFFICIENCY FLEXIBLE SOLAR CELLS

Organoboron Polymers for Photovoltaic Bulk Heterojunctions

We report on the application of three-coordinate organoboron polymers, inherently strong electron acceptors, in flexible photovoltaic (PV) cells. Poly[(1,4-divinylenephenylene)(2,4,6-triisopropylphenylborane)] (PDB) has been blended with poly(3-hexylthiophene-2,5-diyl) (P3HT) to form a thin film bulk heterojunction (BHJ) on PET/ITO substrates. Morphology may be modulated to give a high percentage of domains (10-20 nm in size) allowing exciton separation. The photoelectric properties of the BHJs in devices with aluminium back electrodes were imaged by light beam induced current (LBIC) and light beam induced voltage (LBIV) techniques. Open circuit voltages, short circuit currents and overall …