Degradation mechanisms and stability challenges in perovskite solar cells: a comprehensive review

Perovskite solar cells (PSCs) present a promising alternative to silicon-based solar cells, offering high efficiency, cost-effective production, and flexibility. Despite their potential, challenges such as stability concerns, toxicity, and scaling limitations hinder their widespread commercial adoption. Ongoing research is focused on advancing material innovations and exploring tandem cell configurations to improve both durability and efficiency, aiming to overcome these barriers for broader deployment. Despite these superior properties there is no perfection in every aspect; the perovskite materials suffer from rapid degradation under operational conditions, so this review explores key degradation processes impeding the PSCs long-term stability, including the extrinsic factors which involve exposure to high temperature, humidity, light and intrinsic factors like ion migration, residual strain, and charge trapping. The main outcome of this review is the severe impact of defect density and environmental factors on PSC efficiency and stability. Increased defect density (from 1 × 10¹² to 1 × 10¹⁶ cm⁻³) significantly reduces PSC efficiency, dropping PCE efficiency from 21.69 % to 8 % due to shortened diffusion length (10 to 0.1 µm) and carrier lifetime (20 to 0.002 µs). Additionally, the controlled humidity during fabrication enhances PCE efficiency to 20.19 %, while high humidity yields lower PCE (12.39 %), indicating the importance of defect and environmental management for optimal PSC performance.