Controllable preparation of TiO2 nanowire arrays on titanium mesh for flexible dye-sensitized solar cells

Abstract

TiO2 nanowire arrays (NWAs) with an average diameter of 80nm have been successfully synthesized on titanium (Ti) mesh substrates via hydrothermal method. The effects of preparing conditions such as concentration of NaOH solution, reaction time, and hydrothermal temperature on the growth of TiO2 nanoarrays and its related photovoltaic properties were systematically investigated by scanning electron microscopy, X-ray diffraction, and photovoltaic properties test. The growth mechanism of the Ti mesh-supported TiO2 nanostructures was discussed in detail. Moreover, a parametric study was performed to determine the optimized temperature and time of the dye sensitized process for the flexible dye-sensitized solar cell (DSSC). It is demonstrated that hydrothermal parameters had obvious influence on the morphology and growth density of the as-prepared TiO2 nanoarrays. In addition, the performance of the flexible DSSC depended strongly on the sensitization temperature and time. By utilizing Ti mesh-supported TiO2 NWAs (with a length of about 14μm) as a photoanode, the flexible DSSC with a short circuit current density of 10.49mAcm−2, an open-circuit voltage of 0.69V, and an overall power conversion efficiency of 3.42% was achieved.