Applications of emerging optoelectronic materials : lead sulphide quantum dots and steam cracker tar

Abstract

Optoelectronics covers a wide and varied field of devices and applications, with many requiring different material properties for operation and manufacturing. In this thesis, I describe work performed over the course of my degree to improve the performance and understanding of various optoelectronic materials. In particular, I, with the help of my collegues and collaborators, have focused on two materials with emerging applications in optoelectronic devices: lead sulphide quantum dots (PbS QDs), quantum confined materials primarily used in photovoltaics; and steam cracker tar (SCT), a petrochemical by-product that at the outset of this work was simply a waste product, with no electronic applications demonstrated. This thesis documents the progress made in five distinct projects: the development of direct nanoimprinting as a nanoscale patterning method for PbS QDs and other nanoparticles; experimental and computational work to improve our understanding of the anomalously large Stokes shift in PbS QDs; the development of a novel processing method to produce optoelectronic films from SCT and the demonstration of first applications; an in depth study of SCT as a material for windscreen de-icing, including a demonstration prototype and a technoeconomic analysis; and further optoelectronic study of SCT with the aim of evaluating its potential for use in more complex, active optoelectronics. Finally, this thesis concludes with an outlook on the future prospects of these materials and suggestions for continuing research.