Integrated Calendar

In this presentation I will describe the design rationale, synthesis, characterization, of several organic semiconducting polymers for printed thin-film transistors (TFTs) and photovoltaic cells (OPVs) and understand their charge-transport characteristics as a function of the device architecture/interface modifications (Fig. 1).1 Particularly I will describe the realization of printed organic TFTs with electron mobilities > 3 cm2/Vs and single crystal devices with mobilities > 7 cm2/Vs for. Furthermore, OPV cell with efficiencies >9% are demonstrated.Finally, I will report on recent studies on charge transport using controlled film microstructure and at single crystal heterojunctions.Reference
1. (a) Guo, X.; Quinn, J.; Chen, Z.; Usta, H.; Zheng, Y.; Xia, Y.; Hennek, J. W.; Ortiz, R. P.; Marks, T. J.; Facchetti, A. J. Am. Chem. Soc. (2013), 135, 0-0. b) Usta, H.; Newman, C.; Chen, Z.H.; Facchetti, A. Adv. Mater. (2012), 24, 3678. c) A. Facchetti Chem Mater., 23, 733 (2011). (d) H. Yan, Z. Chen, Y. Zheng, C. E. Newman, J. Quinn, F. Dolz, M. Kastler, A. Facchetti Nature 457, 679 (2009). (e). D. Boudinet, M. Benwadih, S. Altazin, J.-M. Verilhac, E. De Vito, C. Serbutoviez, G. Horowitz, A. Facchetti J. Am. Chem. Soc. 133, 9968 (2011).
2. (a) Fabiano, S.; Musumeci, C.; Chen, Z.; Scandurra, A.; Facchetti, A.; Pignataro, B. Adv. Mater. 24, 951 (2012). (b) I. G. Lezama, M. Nakano, N. A. Minder, Z. Chen, F. V. Di Girolamo, A. Facchetti, A. F. Morpurgo Nature Mater. (2012) 11(9), 788-794.

Many turbulent flows undergo sporadic random transitions after long periods of apparent statistical stationarity. A straightforward study of these transitions, through direct numerical simulation of the governing equations is nearly always impracticable. In this talk, we consider two-dimensional and geostrophic turbulence models with stochastic forces in regimes where two or more attractors coexist. We propose a non-equilibrium statistical mechanics approach to the computation of rare transitions between two attractors. Our strategy is based on the large deviation theory for stochastic dynamical systems (Freidlin-Wentzell theory) derived from a path integral representation of the stochastic process.

Simple wave oscillations in plasmas can produce enormous effects. This talk first explains what is a plasma wave. I then focus on two recently discovered, curious, and potentially useful effects, both mediated by the plasma wave, and both involving wave compression. One effect is resonant Raman backscattering, whereby a long moderately intense laser beam loses its energy to a short counter-propagating beam, producing a much shorter and much more intense pulse. This effect might overcome the material limitations of present technology, enabling the next generation of laser intensities. A second compression effect occurs when the plasma itself is compressed; not only does its temperature increase, but any embedded waves might also increase in energy. For adiabatic changes in time of the density of the plasma medium, the coherent wave energy grows, but, importantly, might then very abruptly lose this energy.