Record stability for perovskite solar cells, efficiency over 20%

EPFL scientists have greatly improved the operational stability of perovskite solar cells by introducing cuprous thiocyanate protected by a thin layer of reduced graphene oxide. Devices lost less than 5% performance when subjected to a crucial accelerated aging test during which they were exposed for more than 1000 hours to full sunlight at 60°C. Perovskite solar cells (PSCs) can offer high light-conversion efficiency with low manufacturing costs. But to be commercially viable, perovskite films must also be durable and not degrade under solar light over time. EPFL scientists have now greatly improved the operational stability of PSCs, retaining more than 95% of their initial efficiencies of over 20 % under full sunlight illumination at 60^oC for more than 1000 hours. The breakthrough, which marks the highest stability for perovskite solar cells, is published in Science . Challenges of stability Conventional silicon solar cells have reached a point of maturation, with efficiencies plateauing around 25% and problems of high-cost manufacturing, heavyweight, and rigidity has remained largely unresolved.