Efficient and stable flexible perovskite solar cells based on graphene-AgNWs substrate and carbon electrode without hole transport materials

摘要

Carbon electrode-based hole transport layer-free perovskite solar cells (C-PSCs) are widely recognized as a competitive candidate towards practical applications, due to their advantages of low-cost, easy-fabrication, and long-term stability. However, fully low-temperature preparation of this type of solar cells on flexible substrates remains a huge challenge. Here, the all carbon electrode-based flexible C-PSCs with the structure of polyethylene terephthalate (PET)/graphene-silver nanowires (graphene-AgNWs)/SnO2/CH3NH3PbI3/Carbon are successfully prepared by low-temperature solution process. By optimizing the fabrication condition, an optimal efficiency of 9.73% is obtained, which is the highest value reported so far for flexible C-PSCs. Meanwhile, these flexible devices demonstrate superior mechanical robustness in comparison with their counterparts fabricated on flexible indium tin oxide (ITO)/PET substrates as well as excellent long-term durability. The present study can provide a simple way to fabricate low cost, highly efficient and highly stable perovskite solar cells for various applications.