Documento PDF - UniCA Eprints - Università degli studi di Cagliari.
Documento PDF - UniCA Eprints - Università degli studi di Cagliari.
Documento PDF - UniCA Eprints - Università degli studi di Cagliari.
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A B S T R A C THybrid interfaces are attracting increasing interest forphotovoltaic applications due to their low cost of productioncompared to tra<strong>di</strong>tional silicon-based systems and easyprocessability. This is the case of polymer/metal oxide systems.In particular, hybrid P3HT/ZnO can be consideredas a possible alternative to organic solar cells because, byreplacing the organic electron acceptor with the inorganicmetal oxide it is, in principle, possible to improve the stabilityas well as the durability of the system.In this thesis, by means of a combination of large scalemolecular dynamics simulations and ab initio methods, westudy at the atomic scale the interface between the polymerP3HT and the ZnO crystalline surface.We investigate the structure and morphology of the polymerat the interface at low and room temperature, we characterizein detail the polymer <strong>di</strong>sorder close to the ZnOsurface and we <strong>di</strong>scuss the implications of this <strong>di</strong>sorderon transport properties. Furthermore, we investigate thepossible presence of residual molecules of solvent at the interfaceafter the synthesis process, that can affect the propertiesof the interface.A novel strategy to improve the polymer/metal oxide interfaceis proposed and investigated. Specifically, we studythe deposition and assembling of zinc phthalocyanine moleculeson ZnO and we investigate the mo<strong>di</strong>fication of the P3HT/ZnOinterface, induced by the use of a ZnPc optically activemolecular interlayer. The structure and morphology of theZnO/ZnPc/P3HT system, <strong>stu<strong>di</strong></strong>ed by molecular dynamicssimulations, are used as starting point for DFT calculations.We <strong>di</strong>scuss the electronic and optical properties ofthis ternary system reporting in<strong>di</strong>cations of an improvementin hybrid photovoltaic devices due to the hinderingof the charge recombination and a better exploitation ofthe solar spectrum.This kind of architecture, theoretically designed by amultiscale pre<strong>di</strong>ctive modeling in the present thesis, is anv