In-situ solvothermal growth of Zn2SnO4 films on FTO glass towards superior dye-sensitized solar cells

Zn2SnO4 hierarchical sphere and Zn2SnO4 "broccoli"-like array films grown on fluorine-doped tin oxide (FTO) glass substrates are successfully produced via a simplistic in-situ solvothermal synthesis process. Herein, the ethyleneglycol (EG), ethylenediamine (En), and polyvinlpyrrolidone K30 (PVP) with NaOH in mixed solvent play the key role in determining the product morphology. The dynamic electron transport/recombination properties are investigated in detail via Intensity-modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS), electrochemical impedance spectroscopy (EIS), and open-circuit voltage decay (OCVD) measurements. The dye-sensitized solar cells (DSSCs) based on three-dimension (3D) hierarchical Zn2SnO4 sphere photoanode showcase better power conversion efficiency (PCE, 0.83 %) than that of Zn2SnO4 "broccoli"-like array (0.69 %), which is predominantly associated with the higher N719 dye loading amount and superior light scattering capacity.