Occlusal Architecture of the Buried Interface Enables Record-Efficiency Flexible Perovskite Photovoltaic Modules with Enhanced In-Plane Bending Mechanical Endurance

Flexible perovskite photovoltaic cells (f-PPCs) have demonstrated enormous potential in portable electronics due to the high power-to-weight ratio characteristic in outdoor and indoor ambient environment. However, the inherent mechanical endurance of f-PPCs remains a major concern. Inspired by industrial strong adhesion coatings, herein, a porous nanoparticle layer is inserted into the buried interface of the perovskite layer to regulate the interfacial adhesion with a smooth hole transporting layer (HTL). As a result, the f-PPCs realizes retaining over 80% of original efficiency after 2000 in-plane bending cycles with the narrow radius of 4 mm. Furthermore, a certified record efficiency of 20.20% is achieved for flexible perovskite solar module, as well as the record efficiency of 31.69% for flexible perovskite indoor photovoltaic module (LED, 1000 lux). A porous nanoparticle layer is inserted between the ITO and perovskite layer to form occlusal architecture, leading to improved interfacial adhesion. Ultimately the flexible perovskite devices show enhanced mechanical reliability against bending.image