Facile transfer fabrication of transparent, conductive and flexible In₂O₃:Sn (ITO) nanowire arrays electrode via selective wet-etching ZnO sacrificial layer

We report a facile transfer fabrication of tin-doped indium oxide (In₂O₃:Sn) nanowires array (ITO NWs) electrode with high transparency and bending stability via selective wet-etching of a sacrificial ZnO layer. The ITO NWs are grown on ZnO (200 nm)/Si substrate by using a vapor-liquid-solid (VLS) method and then subsequently it is soaked in basic solution (1 M NaOH) to dissolve ZnO under-layer selectively, which enables to detach the ITO NWs electrode from the substrate without damage. We found that open-structure and porous nature of the ITO NWs with ITO nanoparticles support facilitate the NaOH solution penetration into the ZnO layer, thus enabling rapid peeling off the ITO NWs, even for a large sized substrate. The fabricated ITO NWs electrode on the PET substrate showed good transparency, conductivity and flexibility, eventually enabling to fabricate a flexible solid-state dye-sensitized solar cell with a satisfactory performance.