Exploiting the vast source of energy provided by the sun is one of the most promising pathways towards reducing fossil fuel use and shifting to renewable energy sources. The development of novel solar cells is thus of high importance to maximise the benefits this approach can provide. In the field of cutting-edge photovoltaic technologies, perovskites have emerged as one of the best-performing candidates for the solar cells of the future. Much of the research into perovskites is now focused on tackling some of the issues they face limiting their potential for industry-level adoption. The implementation of a related class of materials, know as Layered Perovskites (LPKs) is an increasingly popular approach to achieve the requirements of longevity and high efficiencies. Here, the unique combination of properties provided by the alternating organic and perovskite sheets results in a highly-tunable hybrid material that is stable and well-suited to improving performance across a range of perovskite solar cell compositions. Whilst the implementation of LPKs is a well-established avenue of research, questions still remain about some of their fundamental properties. The work presented in this thesis seeks to challenge some of the assumptions that are universally applied to LPKs as a whole. The interplay between the organic components and the perovskite backbone is found to be highly complex, and it is difficult to draw clear relations between the chemistry of the A’ cation, the material structure, and its optoelectronic properties. Many of the highly desirable properties such as improved stability are not strictly applicable to the extremely thin layers that are most widely utilised within solar cells, which readily degrade in ambient conditions. Indeed, the solar cell fabrication process can disrupt the LPK or even remove it entirely, highlighting that great care must be taken when exploring the mechanism behind their benefits to performance and stability.
Marcin Giza (Thu,) studied this question.