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Fullerene–oligothiophene copolymers acting as donor/acceptor segregation modulators improve the device efficiency, giving the highest values for P3HT:PCBM plastic solar cells.

In spite of more than two-decades of studies of molecular self-assembly, the achievement of low cost, easy-to-implement and multi-parameter bottom-up approaches to address the supramolecular morphology in three-dimensional (3D) systems is still missing. In the particular case of molecular thin films, the 3D nanoscale morphology and function are crucial for both fundamental and applied research. Here we show how it is possible to tune the 3D film structure (domain size, branching, etc.) of thin film heterojunctions with nanoscale accuracy together with the modulation of their optoelectronic properties by employing an easy two-step approach. At first we prepared multi-planar heterojunctions with a programmed sequence of nanoscopic layers. In a second step, thermal stimuli have been employed to induce the formation of bulk heterojunctions with bicontinuous and interdigitated phases having a size below the exciton diffusion length. Importantly, the study of luminescence quenching of these systems can be considered as a useful means for the accurate estimation of the exciton diffusion length of semiconductors in nanoscale blends. Finally, nearly a thousand times lower material consumption than spin coating allows a drastic reduction of material wasting and a low-cost implementation, besides the considerable possibility of preparing thin film blends also by employing materials soluble in different solvents.

Systematic radon monitoring in the Gran Sasso Underground Laboratory was performed in order to determine the background radon contribution to the sophisticated experimental apparatus and to check health physics standards for the personnel. As expected, the radon concentrations were found to depend strongly on the ventilation in the three experimental halls. Considerable reductions in the radon concentrations were obtained in 1993, when fresh air was drawn into the laboratory through a pipe and exhaust air was routed into the highway tunnel.

A flow functionalization route has been employed to derivatize single wall carbon nanotubes (SWCNTs) by thienylphenyl groups. The SWCNT derivatives in the most soluble fraction have been characterized by thermogravimetric analysis, DLS analysis, DFT calculations, and UV-vis-NIR, microRaman and IR spectroscopies to study the degree of functionalization, the concentration of SWCNTs in solution, the dimension of the aggregates in solutions, the density of defects, and the presence of the thienylphenyl groups. Thin-film heterojunctions made of SWCNT derivatives and poly(3-hexylthiophene) (P3HT) have been prepared by various methods employing the Langmuir–Schaefer technique, spin-coating and thermal annealing processes. By comparing the batch and the flow functionalizations, a trade-off between solubility, processability and the thin-film opto-electronic properties has been found as a result of the degree of functionalization

Precisely positioning functionalized gold nanoparticles assemblies at planar donor−acceptor interfaces results in 14-fold enhancement of power conversion efficiency in P3HT/PCBM organic solar cells on plastic (ITO/PET) substrates. This result has been achieved by employing naphthalenethiol-capped gold nanoparticles (NT-Au-NPs) produced by laser ablation in liquid and size varied in the 10−30 nm range. Upon surface functionalization with the aromatic thiol, these particles self-assemble in submicrometer aggregates, which give increased light scattering. When these aggregates are deposited in the planar heterojunction between the donor and the acceptor systems, the localized scattering leads to a larger exciton formation just in the region of interest for charge transfer.

Herein a library of hybrid Mn-Anderson polyoxometalates anions are presented: 1, [(MnMo6 O18 )((OCH2 )3 -C-(CH2 )7 CHCH2 )2 ](3-) ; compound 2, [(MnMo6 O18 )((OCH2 )3 C-NHCH2 C16 H9 )2 ](3-) ; compound 3, [(MnMo6 O18 )((OCH2 )3 C-(CH2 )7 CHCH2 )1 ((OCH2 )3 C-NHCH2 C16 H9 )1 ](3-) ; compound 4, [(MnMo6 O18 )((OCH2 )3 C-NHC(O)CH2 CHCH2 )2 ](3-) and compounds 5-9, [(MnMo6 O18 )((OCH2 )3 C-NHC(O)(CH2 )x CH3 )2 ]), where x = 4, 10, 12, 14, and 18 respectively. The compounds resulting from the cation exchange of the anions 1-9 to give TBA (a) and DMDOA (b) salts, and additionally for compounds 1, 2 and 3, tetraphenylphosphonium (PPh4 ) (c) salts, are explored at the air/water interface using scanning force microscopy, showing a range of architectures including hexagonal structures, nanofibers and other supramolecular forms. Additionally the solid-state structures for compounds 1c, 2c, 4a, 6a, 9a, are presented for the first time and these investigations demonstrate the delicate interplay between the structure of the covalently derivatised hybrid organo-clusters as well as the ion-exchange cation types.

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