A phthalocyanine-based polycrystalline interlayer simultaneously realizing charge collection and ion defect passivation for perovskite solar cells

Abstract

In the quest for sustainable energy solutions, perovskite solar cells have emerged as a promising avenue due to their remarkable efficiency and cost-effectiveness. However, their widespread adoption is hampered by performance degradation issues primarily attributed to ion migration and vacancy formation within halide perovskite films. To mitigate the impact of ion defects, a passivation layer, which typically acts as a barrier for carriers, is employed. Nonetheless, the requirement for extreme thinness to avoid increasing series resistance complicates the manufacturing process. In this study, we introduced gallium phthalocyanine hydroxide (OHGaPc), a p-type organic semiconductor with Lewis base functionality, as a passivation layer to mitigate performance degradation in perovskite solar cells. We demonstrated that this material passivates halide vacancies by being a Lewis base and promotes efficient charge transport as a p-type semiconductor. This dual functionality of OHGaPc not only enhances the stability and performance of perovskite solar cells but also simplifies the manufacturing process by obviating the need for ultra-thin insulating films. Our findings underscore the significance of leveraging the properties of Lewis bases and p-type semiconductors in improving charge extraction and overall cell efficiency, setting a new direction in the development of durable and efficient perovskite solar cells.