Microfluidics-based ZnO 3D-hierarchical nanostructures for stable and high efficiency perovskite solar cells
摘要
Microfluidics-based reactors allow governable synthesis of micro-/nanostructures for an extensive range of applications from materials science, bioengineering to drug delivery. In the current study, hierarchical ZnO nanostructures composed of nanosheets are firstly produced using a viable and rapid method without the use of any template or surfactant via a microfluidic reactor in a continuous motion. This method represents a clear and systematic route to manufacture the 3D ZnO nanostructures compared to the conventionally used synthesis schemes. Perovskite solar cells (PSCs) are fabricated using the produced 3D ZnO nanosheets for the first time ever. The PSCs based on ZnO nanosheets produces the average power conversion efficiency (PCEavg) of 15.87% and the maximum power conversion efficiency (PCEmax) of 18.97%, thanks to unique nanostructure which increases the chances of improved perovskite penetration into it and rapid electron transport. Conversely, devices based on ZnO nanoparticles lack in performance (PCEavg = 11.14%) compared to 3D ZnO nanosheets owing to their zero dimensional geometry and slow electron transport.