High-performance ZnO nanosheets/nanocrystalline aggregates composite photoanode film in dye-sensitized solar cells

Novel ZnO nanosheets (NSs)/nanocrystalline aggregates (NAs) composite films were constructed by depositing a ZnO NAs directly on the surfaces of pre-fabricated ZnO NSs through a dip-coating method. The morphology and performance of dye-sensitized solar cells (DSSCs) were studied. The top layers of ZnO NAs improved the light scattering of composite films. The bottom layers of ZnO NSs consisted of 20-30 nm nanoparticle has a single crystal structure. In addition, ZnO NSs is vertical conductive substrate, so the bottom layers of ZnO NSs layer have a larger specific surface area and good electron transport. Based on the above advantages, the photoelectric conversion efficiency (PCE) of DSSCs assembled by the ZnO NSs/NAs composite films is 7.95%, which is 81.51% higher than that of ZnO NSs and is close to the highest PCE that has ever been reported (8.03%).