Vertically building Zn2SnO4 nanowire arrays on stainless steel mesh toward fabrication of large-area, flexible dye-sensitized solar cells

Zn2SnO4 nanowire arrays were for the first time grown onto a stainless steel mesh (SSM) in a binary ethylenediamine (En)/water solvent system using a solvothermal route. The morphology evolution following this reaction was carefully followed to understand the formation mechanism. The SSM-supported Zn2SnO4 nanowire was utilized as a photoanode for fabrication of large-area (10 cm x 5 cm size as a typical sample), flexible dye-sensitized solar cells (DSSCs). The synthesized Zn2SnO4 nanowires exhibit great bendability and flexibility, proving potential advantage over other metal oxide nanowires such as TiO2, ZnO, and SnO2 for application in flexible solar cells. Relative to the analogous Zn2SnO4 nanoparticle-based flexible DSSCs, the nanowire geometry proves to enhance solar energy conversion efficiency through enhancement of electron transport. The bendable nature of the DSSCs without obvious degradation of efficiency and facile scale up gives the as-made flexible solar cell device potential for practical application.