Improving the processability of large-area conjugated polymer thin films for use in organic and tandem silicon/perovskite photovoltaics
- Runser, Rory
- Advisor(s): Lipomi, Darren J
Thin films of polymers are required for a myriad of technological applications, ranging from simple protective coatings to advanced multilayer laminates for flexible electronic devices. A class of polymers called conjugated polymers is of particular interest due to their ability to transport electronic charge while retaining mechanical deformability. These mechanical and electronic properties are easily tunable via synthetic modification of the polymer structure, resulting in a rich diversity of materials available for study. As such, conjugated polymers have been widely incorporated in next-generation thin-film photovoltaic technologies, as a layer added to improve charge transport, light absorption, or both. Nevertheless, the vast majority of studies of these materials utilize solution processing techniques (e.g. spin-coating, blade-coating, etc.) that inherently require planar substrates. This dissertation will discuss several polymer thin film processing techniques that yield large-area free-standing polymer films, which can then be coated onto a variety of flexible, textured, and non-planar surfaces. The development and characterization of a continuous, roll-to-roll deposition process is used to generate large-area organic solar cells, as well as to coat conjugated polymer films uniformly onto a textile substrate for flexible fabric-mounted PV. In addition, a batch process deposition technique will be shown for application of polymer films onto the surface of micro-pyramids, a key requirement for tandem perovskite silicon solar cells. Lastly, solar cell encapsulation techniques for extending the lifetime of perovskite solar cells will be discussed. Ultimately, such developments will help to advance the processability and performance of next-generation photovoltaic technologies.