ZnO nanostructures for efficient perovskite solar cells

Controlled ZnO nanostructures were synthesized via spin-coating and in situ thermal decomposition processing using ZnO paster with/without zinc acetate as precursor. The perovskite CH₃NH₃PbI₃ solar cells (PSCs) based on these ZnO nanostructures were fabricated and their photovoltaic performances have also been investigated. Effects of zinc acetate concentration on morphologies of ZnO nanostructures and the photovoltaic properties of corresponding PSCs have been discussed. Interestingly, the morphologies of ZnO nanostructures were varied from separate nanoparticles to interconnect net-like nanostructures and the space of ZnO nanoparticles became large when the concentration of zinc acetate was increased from 0 to 0.13 M. The space and the connection degree of ZnO nanostructure obtained from 0.05 M zinc acetate are the best choice for perovskite infiltration and charge transport, which leads to corresponding cells have highest power conversion efficiencies (PCE) of 9.30 %. Post-treatment of ZnO nanostructures improved further Voc and FF, leading to PCE to 13.1 %.