Characterisation and optimisation of electrodes for applications in organic photovoltaics

This thesis presents research on nanostructured electrodes utilized in organic photovoltaic devices (OPVs). The need for new types of electrodes is motivated by both the limitations of currently used electrode materials used as transparent electrode, & the rapid development of the technology & its introduction to alternative applications. The thesis begins with an introduction (Chapter 1) and two chapters detailing the experimental procedures (Chapter 2) and analytical approaches (Chapter 3) Chapter 4 presents work on passivation of Cu with Sm. Cu is known for its fantastic electrical conductivity and low price. Although Cu is prone to oxidation under ambient conditions, forming detrimental oxides & hydroxides, deposition of a thin Sm layer markedly inhibits oxidation, slowing it by more than an order of magnitude. Chapter 5 regards elucidation of the phenomenon of minimising the condensation of evaporated Ag atoms onto highly fluorinated surfaces. The exploration of properties of perfluorinated methacrylate films allowed to elucidate the mechanism and driving factors that minimise condensation of Ag. Those, allowed formulation of design rules for potential low condensation coefficient (C) materials. Chapter 6 describes the novel processes for fabrication of Ag nanostructures directly on top of OPV device stacks and investigates the limitations of this methodology. A successful fabrication various of top-electrodes including semitransparent grid electrodes, an array of micrometric dome mirrors, and a periodic array of nanoholes has been reported. Chapter 7, the final chapter of this thesis includes concluding remarks, posxx sible ways to forward the research area and some preliminary data that goes beyond the state-of-the-art and is considered out of scope for other chapters.