Toward Stable and Efficient Perovskite Solar Cells for Space and Earth-Based Applications: A Nanoscale Investigation

This thesis explores the development of stable and efficient perovskite solar cells (PSCs) for terrestrial and space applications, emphasizing nanoscale investigations of their structural and photovoltaic (PV) properties. In Chapter 1, the study begins with the motivation to transition to renewable energy sources to combat climate change, highlighting the advantages of solar energy, including space-based solar power (SBSP). The challenges faced by current PV technologies, especially PSCs, are addressed, focusing on improving stability and efficiency for both Earth and space applications. In Chapter 2, a literature review explored various phenomena occurring in PV materials due to micro- and nanostructural heterogeneity, with a particular focus on grain boundaries (GBs). In Chapter 3, Atomic Force Microscopy (AFM) and Kelvin Probe Force Microscopy (KPFM) were reviewed as the primary characterization techniques used to investigate interfacial phenomena, halide segregation, degradation processes, and charge transport dynamics in both conventional 3D and quasi-2D perovskite solar cells (PSCs). Various KPFM methods, including mapping, time-resolved measurements, and varying the wavelength of illuminated light, were applied based on the specific requirements for investigating each phenomenon. KPFM was utilized to investigate key nanoscale properties in conventional PSC devices, effectively addressing challenges in the field. In Chapter 4, it was revealed using KPFM that Al2O3 nanoparticles improved surface uniformity and charge extraction of the HTL. Halide segregation under light exposure, which can be mitigated through interface engineering using the lamination method was investigated. These results demonstrate the versatility of KPFM in exploring interfacial engineering and halide dynamics. In Chapter 5, a systematic investigation using various KPFM methods on quasi-2D PSCs demonstrated the charge transport mechanism depending on the grain orientation and enhanced photocurrent at GBs. In Chapter 6, proton-induced damage to organic A-site cations was found to be a major factor contributing to perovskite degradation post-irradiation. PDAI2 surface treatment was identified as a key strategy for mitigating proton-induced degradation, significantly enhancing the radiation resilience of wide-bandgap PSCs. These insights provide a foundation for the rational design of PSCs, advancing their stability, performance, and scalability for diverse energy applications.