Eu doping for hierarchical ZnO nanocrystalline aggregates based dye-sensitized solar cell

• Hierarchically structured Eu-ZnO aggregates were successfully synthesized.
• Eu-ZnO cell shows higher energy conversion efficiency than ZnO cell.
• Eu-ZnO exhibits enhanced electron injection and transport properties.

Hierarchically structured europium-doped zinc oxide (Eu-ZnO) nanocrystalline aggregates were synthesized through solvothermal method. The dye-sensitized solar cell (DSC) fabricated using the Eu-ZnO aggregates as photoanode exhibits effective electron injection and enhanced electron transport properties, which greatly improve Jsc (12.0 to 15.5 mA cm− 2) and η (4.5 to 5.7%), compared with those corresponding values of undoped ZnO aggregates based DSC. Furthermore, the Eu-ZnO DSC showed low efficiency decay with no more than 6% loss in 30 days, demonstrating an effective way to increase the cell efficiency by the doping of hierarchical ZnO nanocrystalline aggregates as well as a great potential for practical application.