FOR MORE INFORMATION: Tullio Toccoli - +39 0461314827 - tullio.toccoli@imem.cnr.it
Supersonic molecular beams deposition is a powerful method to study the growth processes of organic molecular semiconductors. The possibility to tune the kinetic energy of the impinging molecules such as their momentum open different pathway not accessible with other vacuum deposition techniques [1]. Optimizing the growth parameters such as kinetic energy and momentum, possible with supersonic beams, it is possible to drive the molecular assembling obtaining better ordered films with better optical and electronic properties [2]. In fact, the supramolecular assembling processes give the possibility to realize devices with better functionality for application in sensing, to fabricate light emitting devices and photovoltaic cells.The molecular doping is studied to develop a new class of emitting devices and photovoltaic cells [3].
1) Island size distribution after 10 min of exposure to a supersonic beam of molecules with a kinetic energy of 7.0 eV (a) and 3.5 eV (b) incidence angles Θ = 0, 45° and 75°.
2) Adsorption probability normalized to that for normal incidence growth (zero parallel momentum). The incidence angle θ varied from 0° to 80° with respect to the normal to the surface. The inset shows how the molecular momentum is divided into the // and ┴ components.
3) Energy transfer from picene to pentacene. The figures show: A) how the PL spectra change from pure picene to the doped pentacene films. B) Photoluminescence dynamics of pentacene-doped picenethin films detected at 445 nm (a) and at 590 nm (b).
[1] S. Gottardi, T. Toccoli, Y. Wu, S. Iannotta, P. Rudolf, Growth dynamics in supersonic molecular beam deposition of pentacene sub-monolayers on SiO2, Chemical Communications, 50 (2014) 7694-7697, DOI: 10.1039/c4cc01656d
[2] S. Gottardi, T. Toccoli, S. Iannotta, P. Bettotti, A. Cassinese, M. Barra, L. Ricciotti, and Y. Kubozono, Optimizing Picene Molecular Assembling by Supersonic Molecular Beam Deposition, Journal of Physical Chemistry C 116 (2012) 24503-24511
[3] T. Toccoli, P. Bettotti, A. Cassinese, S. Gottardi, Y. Kubozono, M. A. Loi, M. Manca, R. Verucchi, Photophysics of Pentacene-Doped Picene Thin Films, J. Phys. Chem. C 2018, 122, 29, 16879-16886