UC San Diego

Optoelectronic materials and devices are ubiquitous in the modern world. Thin-film processing of these materials is essential in a tremendous range of applications such as consumer electronics, healthcare, defense, scientific instrumentation, and of particular relevance to this work, renewable power generation through photovoltaics. Typical processing of these materials occurs from either the vapor, liquid, or solution phases, but all of techniques come with various downsides and limitations. Much less common is the processing of thin films directly from the solid phase. That is, the creation of standalone thin films which are subsequently transferred onto the substrate. Such an approach is largely unexplored, and this work has focused on demonstrating some of the unique processing routes which become available when processing from this phase. Particularly, this work focuses on: 1) The solid-phase processing of thin films of conjugated polymers to form conformal, functional coatings on textured light trapping surfaces. 2) The formation of freestanding films of conjugated polymers to then be transferred onto sensitive substrates (e.g. perovskites) to serve as a functional device layer, but applied in a manner that is devoid of liquid solvents. 3) The use of freestanding films of conjugated polymers as a sacrificial substrate onto which transparent conductive oxides can be sputtered, forminga freestanding bilayer, and subsequently transferred to complete perovskite solar cells without subjecting the sensitive perovskite layer to damage from the sputter process.