The intrinsic instability of lead halide perovskite solar cells

Perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology due to their remarkable power conversion efficiencies and low-cost fabrication processes. However, their long-term operational stability remains a critical challenge for commercialization. This review systematically examines the intrinsic instability factors inherent to PSCs, with a focus on material defects, ion migration, lattice strain, interface-induced degradation, and unstable precursor solution. Defects and their migration under operational stresses trigger non-radiative recombination and lattice decomposition. Ion migration, exacerbated by electric fields and illumination, leads to phase segregation and electrode corrosion. Lattice strain, originating from thermal expansion mismatch and crystallization processes, significantly influences charge recombination and phase stability. Interfacial energetics and mismatched energy levels further induce charge accumulation and efficiency loss. Additionally, chemical side reactions in precursor solutions introduce impurities and defects that compromise film quality and device longevity. This work consolidates recent advances in understanding these degradation pathways. By addressing these intrinsic challenges, this review aims to guide the development of durable perovskite photovoltaics toward commercial reality.