Methodologies to Improve the Stability of High-Efficiency Perovskite Solar Cells

Organic-inorganic lead halide perovskite solar cells (PSCs) have attracted significant interest from the photovoltaic (PV) community due to suitable optoelectronic properties, low manufacturing cost, and tremendous PV performance with a certified power conversion efficiency (PCE) of up to 26.5%. However, long-term operational stability should be guaranteed for future commercialization. Over the past decade, intensive research has focused on improving the PV performance and device stability through the development of novel charge transport materials, additive engineering, compositional engineering, interfacial modifications, and the synthesis of perovskite single crystals. In this Account, we provide a comprehensive overview of recent progress and research directions in the fabrication of highly efficient and stable PSCs, including key outcomes from our group. We begin by highlighting the critical challenges and their causes that are detrimental to the development of stable PSCs. We then discuss the fundamentals of halide perovskites including their optical and structural properties. This is followed by a description of the fabrication methods for perovskite crystals, films, and various device architectures. Next, we introduced target-oriented key strategies such as developing high-quality single crystals for redissolution as a perovskite precursor to fabricate phase-stable and reproducible PSCs, along with reduced material costs, employing multifunctional additives to get uniform, robust, and stable perovskite films, and interfacial engineering techniques for effective surface and buried interface defect passivation to improve charge transport and long-term stability. Finally, we conclude with a critical assessment and perspective on the future development of PSCs. This Account will provide valuable insights into the current state-of-the-art PSCs and promising strategies tailored to specific roles that can be combined to manipulate the perovskite structure for novel outcomes and further advancements.