De Girolamo Del Mauro A.,Portici Research Center |
Nenna G.,Portici Research Center |
Bizzarro V.,IMAST Portici |
Grimaldi I.A.,Portici Research Center |
And 3 more authors.
Journal of Applied Polymer Science | Year: 2011
Transparent and conductive nanocomposite films were spin-coated with the use of undoped and dimethyl sulfoxide (DMSO)-doped polyaniline (PANI)-poly(styrene sulfonate) (PSS) dispersions. The prepared dispersions were investigated in terms of their nanoparticle size distributions, and the corresponding films were morphologically, optically, and electrically characterized. These films were used as hole-injection layers (HILs) in organic light-emitting diode (OLEDs), and the device performances were compared to a reference device without an HIL. The device based on the PANI-PSS layer showed the best electrooptical characteristics, lowest switch-on voltage, and improved efficiency. In particular, the device efficiency grew about three times with the introduction of the PANI-PSS layer (1.20 Cd/A) and about two times with the introduction of the DMSO-doped PANI-PSS film (0.77 Cd/A) compared to an OLED without an HIL (0.4 Cd/A). These results indicate that the device with the undoped PANI-PSS was the more suitable one to be used as an HIL in an OLED device. © 2011 Wiley Periodicals, Inc.
Castaldo A.,Portici Research Center |
Addonizio M.L.,Portici Research Center |
Antonaia A.,Portici Research Center |
Nicotra G.,CNR Institute of Neuroscience
Physica Status Solidi (C) Current Topics in Solid State Physics | Year: 2012
Starting from stratification of alternating thin films of Si and ZnO produced by sputtering technique, followed by an annealing process at a sufficiently low temperature (560 °C) under vacuum (10 -4 mbar), we were able to form crystalline nano-aggregates of Si and ZnO in a dielectric matrix of zinc silicate and silicon oxide. The grain size of the Si crystallites depended on the Si/ZnO ratio in the starting material and on the annealing duration. Materials with tuned band gaps have been produced. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.