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Nickel oxide (NiO) thin films with thickness ranging in the interval 0.2 -3.5 μm have been deposited onto conductive transparent substrate via the method of plasma-assisted rapid discharge sintering (RDS) with microwave heating starting from NiO nanoparticles with diameter 50 nm. The optical and electrochemical properties of the RDS NiO films in the pristine state were characterized in non aqueous electrolyte with the solvent 3-methoxy-propionitrile (3-MPN). Upon electrochemical cycling of NiO in 3-MPN we observed two characteristic oxidation peaks referring to the two nickel centred processes Ni(II)→Ni(III) and Ni(III)→Ni(IV), which are both localized prevalently on the surface of the metallic oxide. The oxide films prepared with the RDS method were also sensitized with different types of commercial dyes, either organometallic (N719, black dye) or organic (squaraine 2, erythrosine B), to compare the corresponding p-type dye-sensitized solar cells (p-DSCs). All dyes here employed matched the energies of their frontier orbitals with the upper edge of NiO valence band and the redox level of the triiodide/iodide couple. The comparison of the performances of the p-DSCs based on RDS NiO which differed exclusively for the nature of the sensitizer showed that the extent of electronic conjugation in the structure of the dye is crucial for the control of the photovoltaic performance of the corresponding p-DSC.

This chapter details how plasma treatments can be used to tailor the wettability of polymers. A plasma is an excited gas, and exposure of a polymer to a plasma discharge generally results in an enhancement in surface energy and associated with this is an increase in wettability. The effect however can be short lived due to hydrophobic recovery. In this review the use of both low and atmospheric plasmas for the activation of polymers will be discussed, as will the use of these plasmas for the deposition of plasma polymerised coatings. The latter can be used to produce polymer surfaces with tailored functionalities, thus achieving stable water contact angles ranging from superhydrophilic to superhydrophobic, as required.This review briefly introduces plasmas and plasma processing and includes an overview of typical plasma treatment sources. This is followed by a review of the use of plasma discharges to treat polymers and in particular to enhance their surface energy, which is important for example in achieving enhanced adhesive bond strength. The final section of this chapter focuses on the deposition of plasma polymerised coatings and how these can be used to tailor both surface chemistry and morphology. Thus the wettability of polymer surfaces can be controlled.

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