Characterization and reliability testing of next-generation photovoltaic materials and innovative cell structures.

This thesis investigates advanced photovoltaic technologies with the aim of improving efficiency and stability, focusing on antimony chalcogenides, crystalline silicon heterojunctions (SiHJ), and transition metal oxide (TMO)-based selective contacts. Despite the different materials and architectures, all technologies are limited by the presence of defects and by the quality of their interfaces, which directly impact carrier collection and device efficiency. For antimony chalcogenides (Sb₂S₃ and Sb₂Se₃), electrical analyses and deep-level spectroscopy revealed deep traps and non-ideal band alignments. Sulfur treatments and ZnO/CdS buffers improved Sb₂S₃ performance, though devices remained limited by recombination. In Sb₂Se₃, capacitance transients showed that conventional rate-window analysis is unreliable, as thermally activated filling processes affect carrier transport dynamics. SiHJ solar cells were examined as a reference high-efficiency technology. Stress tests (steps with rising temperature, constant high temperature, light soaking, damp heat) demonstrated strong stability, with significant degradation only under combined heat and humidity. LBIC and EBIC mapping further confirmed recombination at edges and defects. Finally, MoOₓ contacts were explored as alternatives to doped a-Si:H layers. Simulations guided by experimental J–V data highlighted trap-assisted tunneling as the dominant transport mechanism. Overall, the work provides a comprehensive analysis of defect-related limitations and supports the optimization of high-performance, reliable, and sustainable solar cells.