Towards 30% efficiency and 20-year lifetimes: the evolving landscape of perovskite photovoltaics

Over the last ten years, metal halide perovskite solar cells (PSCs) have advanced significantly and are now strong contenders for future third-generation solar technology. Back in 2009, the first single-junction PSCs had power conversion efficiencies (PCEs) of 3.8%. The current stated efficiency is 34.8 % for tandem structures, which is close to or even higher than crystalline silicon. These gains come from better perovskite materials, improved device designs, and advances in layer interactions. New approaches like mixed-cation or halide alloys, layered structures, and stronger transport layers have helped address defects, carrier loss, and stability. Still, major challenges remain in moving PSCs from the lab to real-world use. Main issues include degradation, hysteresis, halide migration, lead toxicity, and scalability. Recent efforts to address these problems include lead-free materials, better encapsulation, recycling, new passivation methods, MXenes, two-dimensional materials, and using machine learning for optimization. Standardizing stability tests and adopting circular-economy practices are important for making PSCs more reliable, consistent, sustainable, and market-ready. This review covers progress from 2021 to 2025, focusing on new materials, device designs, and sustainability. By considering efficiency, stability, and scalability together, it suggests ways to reach over 30% efficiency and lifetimes of more than 20 years. As materials science, device physics, and environmental policy come together, PSCs could play a big role in renewable energy.