[en] Highlights: • ZnO nanorods were synthesized using new set of starting reagents. • The prepared ZnO nanostructures were utilized as insulating shell on TiO₂ film in DSSCs. • Effect of morphology and thickness of ZnO shell on efficiency were studied. • Using ZnO shell led to an increase in DSSCs efficiency from 4.66 to 7.13% (~40% improvement). • Thickness of ZnO shell has crucial effect on overall energy conversion of DSSCs. Herein, rod-like ZnO nanostructures were synthesized via a novel hydrothermal route using Zn(OAc)₂, ethylenediamine and hydrazine as a new set of starting reagents. The as-synthesized products were characterized by techniques including XRD, EDS, SEM, XPS, Pl and FTIR. The prepared ZnO nanostructures were utilized as shell on TiO₂ film in DSSCs. Effect of precursor type, morphology and thickness of ZnO shell (number of electrophoresis cycle) on solar cells efficiency were well studied. Our results showed that ethylenediamine has crucial effect on morphology of synthesized ZnO nanostructures and using ZnO nanostructures leads to an increase in DSSCs efficiency compared to bare TiO₂ from 4.66 to 7.13% (~40% improvement). Moreover, highest amount of solar cell efficiency (7.13%) was obtained by using ZnO nanorods with two cycle of electrophoresis for deposition.