Chinese researchers have systematically addressed challenges in the efficiency and stability of flexible tandem solar cells, representing an advancement in silicon-based flexible photovoltaics. The study, led by researchers from Soochow University, was published in the journal Nature.
The commercialization of flexible crystalline silicon/perovskite tandem solar cells has encountered two main obstacles: their efficiency has lagged behind rigid counterparts, and their interfaces have been prone to delamination and degradation during repeated bending or under demanding conditions.
To mitigate these issues, the research team implemented a dual-layer buffer designed with a "loose-tight" structure. This design aims to dissipate mechanical stress while preserving efficient charge transport at the nanoscale. Additionally, they developed a method for preparing hydrogen-doped indium-cerium oxide films using reactive plasma deposition. This process is intended to minimize interfacial sputtering damage and optimize energy level alignment.
These advancements have led to a certified conversion efficiency of 33.6 percent on an ultra-thin 60-micrometer silicon substrate, setting a new efficiency record for flexible tandem cells. A large-area device, measuring 261 square centimeters (standard wafer size), also achieved an efficiency of 29.8 percent, marking a world record for flexible tandem cells of that scale. The devices demonstrated mechanical durability, retaining 97 percent of their initial efficiency after 43,000 extreme bending cycles.
This work provides a scientific and technical foundation for the potential large-scale application of flexible photovoltaics and presents new opportunities for the silicon-based solar industry.