Low temperature transfer of well-tailored TiO₂ nanotube array membrane for efficient plastic dye-sensitized solar cells

Transferring semiconductor film onto plastic substrate for efficient flexible photovoltaic devices with good mechanical stability against shape wrench is always a big challenge. In this work, well-designed TiO₂nanotube array (TNTA) membrane is achieved by a combination of hot-water-soaking and TiCl₄post-treatment for efficient plastic DSSCs. In this engineered TiO₂architecture, the TiO₂particle decorated and nanowire capped TNTA hybrid structure provides not only enormous dye-loading amount and excellent light scattering/trapping effects for superior light harvesting efficiency, but also fast charge transport along the 1D aligned TNTA scaffold. More importantly, the thin and mesoporous TiO₂layer deposited on the bottom surface of TNTA makes it is possible to form mechanical interlocking between TNTA membrane and the adhesive layer to insure the excellent mechanical stability and efficient electron transfer from the TNTA membrane to the substrate. The plastic DSSCs based on the well-tailored TNTA membranes yield an exciting efficiency of 6.25% and at the same time maintain 90% of its initial efficiency after hundreds of bending cycles.