The field of organic photovoltaics has seen many significant findings over the last two decades. It is now a very active area of research generating thousands of publications, resulting in advancements in a multi-disciplinary setting. The research described in the body of this thesis aims to investigate the use of new materials and architectures in the fabrication of organic photovoltaics. An approach to incorporate carbon nanotube-Buckminster fullerene hybrid materials into the blended active layer of organic photovoltaic devices is introduced and the effects on devices are elucidated. It is found that the use of cut (barrel) single walled carbon nanotubes was the least detrimental to device performance. The use of alternative methods to fabricate or replace commonly used materials and inter-layers (PCBM, ITO, PEDOT:PSS) in the device structure are presented. The use of thin metal films such as silver and gold is shown to be viable and interesting alternatives to ITO. Layer-by-layer assembly of PEDOT:PSS and electrochemically deposited alternatives are found to have similar performance to standard devices. The fabrication and characterization of a new vertically orientated organic photovoltaic device architecture, the stack device, is presented with a proposed optical model to describe the experimental findings. In particular, the optical mechanism responsible for the operation of the stack device is determined to be frustrated total internal reflection. The new architecture is applied to the fabrication of devices using the standard P3HT:PCBM active layer resulting in an increase in performance.
Curran, Seamus and Cafolla, Attilio A.