Remote plasma assisted fabrication of functional organic and hybrid thin films and supported nanostructures

Résumé

In general, functional materials are categorized as those materials which possess particular native properties and functions of their own. Examples of these properties are: ferroelectricity, piezoelectricity, magnetism, temperature variations, pressure variations and optical functions. There exists an immense range of functional materials. For instance, optical materials, including lasers, Raman scattering, fluorescence and phosphorescence, are functional materials. Moreover, electrical, magnetics and dielectrics materials are also examples of functional materials, such as semiconducting devices and superconductors, piezoelectrics, ferroelectrics, optical fibres and liquid crystals. On the other hand, functional materials include ceramics, metals, polymers and organic molecules. In recent years, one of the main goals of materials science is the fabrication of new functional materials because of their applications in electronics, informatics and telecommunications. Its continuous development is based on environmental aspects (energy-efficiency, life-cycle issues, recycling or renewable solutions) and cost reduction aspects (energy saving factors in production). The main objective of this thesis is the development of novel multifunctional thin films and supported nanostructures by using remote plasma processes. The thesis is subdivided into eight chapters. At first, Chapter 1 includes the Introduction to the whole work developed throughouth the thesis. Chapter 2 gathers an overview of the thesis in Spanish language. Chapters 3-4 (¿Conformal dielectric organic thin films for molecular electronics¿ and ¿Wetting and anti-freezing properties of adamantane coatings: from thin films to 3D networks¿) study the processability and applications of organic thin films as coatings through its functionalities. These films are fabricated from a precursor of adamantane (C10H16) by RPAVD technique. Separated Chapters 3-4 provide the analysis of two properties of adamantane RPAVD films: dielectric and anti-freezing properties. Later, Annex 1 (¿Adamantane RPAVD: from thin films to 3D networks¿) shows a complete characterization of these adamantane films. After that, this section establishes the control of properties of this type of films, as well as the development of the synthesis of this precursor as supported nanostructures. In addition, it also illustrated that some properties of the films founded in this work can be extended to whole RPAVD materials. Chapter 5, ¿Multicolored emission and lasing in DCM-Adamantane plasma nanocomposites¿ introduces new RPAVD thin films using the combination of a dye laser (4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran, C19H17N3O) and adamantane as precursors. These films exhibit different functionalities that are related to optical properties. In the first instance, this Chapter studies the chemical characterization of the films grown by the mixture of the two precursors. Later, its optical properties are adjusted for a final processing. Finally, it is presented the achievements in the integration of one type of these films in a laser device. Chapter 6 (¿Soft Plasma processing of Organic Nanowires¿) studies a general procedure for the fabrication of hierarchical and hybrid 1D nanostructures from metalloporphyrin, metallophthalocyanine and perylene diimide by plasma processing. The method also provides a template route for the synthesis of supported metal and metal oxide nanostructures by oxygen plasma treatments. In this way, Chapter 7 (¿Highly porous ZnO thin films and 1D nanostructures by remote plasma processing of Zn-phthalocyanine¿) studies the plasma-assisted oxidation of ZnPc in the form of thin film or nanowires to nanostructured ZnO materials. We analyze the characterization of both thin film and supported nanostructures of these hybrid materials. On the other hand, we also evaluate their applications in connection with Annex 2 where we present ZnO thin films from inorganic precursor (ZnEt2) discussed as photonic sensor of oxygen. It is worth to notice that the end of Annex 1 introduces some advances in the synthesis method of functional RPAVD materials. We have developed a new RPAVD structure named nanofabric. Nanofabric is the result of a combination of two accomplishments performed in the present work: the synthesis of hierarchical nanostructures described in Chapter 6, and the process of adamantane by RPAVD detailed in Chapters 3-4 and this Annex.