Transparent conducting oxides on polymeric substrates by pulsed laser deposition

This thesis describes the research on thin films of transparent conducting oxides (TCOs) on polymeric substrates manufactured by pulsed laser deposition (PLD). TCOs are an indispensable part in optoelectronic applications such as displays, solar cells, light-emitting diodes, etc. At present, in many of these applications there is an increasing need for the use of flexible, cheap and lightweight substrates. Such polymer substrates however, limit the deposition temperature of thin films which results in deteriorated properties of the TCO. A profound understanding of the fundamental aspects of transparent conductors is required in order to improve either the properties of existing materials, or design new types of TCOs. These insights are of great scientific importance for the realization of high performance TCOs on polymer substrates. This research focuses on thin film growth by PLD. This technique is a powerful tool for thin film research. A large freedom of choice in independently controllable deposition parameters allows one to quickly obtain results on the exploration and optimization of existing and new materials. The ablated species can be tuned over a large energetic range, enabling optimum conditions at lower substrate temperatures normally used for high performance TCO materials. This makes the deposition of TCOs on heat resistive substrates possible. The substrates utilized in this research are all commercial available and commonly used materials such as translucent polyethylene terephthalate (PET). Analysis of the PLD grown films is done by a variety of tools to obtain information on the electrical, optical and structural properties as well as the thin film composition.