Universal Non-destructive Interconnection Layer Engineering for Efficient and Stable Perovskite Tandem Photovoltaics

Abstract

Broader ContextTandem solar cells (TSCs) integrating absorbers with complementary bandgaps represent a compelling route to exceed the efficiency limit of single-junction photovoltaics. Among emerging architectures, all-perovskite and perovskite/organic tandems have garnered increasing attention, owing to their high-performance potential and compatibility with low-cost solution processing. However, the widely used hole transport layer (HTL) in both architectures, poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), typically dissolved in aqueous solution, is inadvertently deteriorating the underneath wide bandgap perovskite sub-cell. Herein, we synthesized an isopropanol-dispersible PEDOT, which is non-destructive to perovskite films. This innovative formulation mitigates moisture erosion and recovers the performance loss attributed to HTL-induced damage. It also reduces interfacial losses for the narrow bandgap tin-lead perovskite solar cells and improves hole extraction. The water-free HTL demonstrates its superiority in both all-perovskite and perovskite/organic TSCs, establishing a universally applicable and water-free HTL for enhancing the efficiency and operational stability of all-perovskite and perovskite/organic tandems photovoltaics.