A first report on the fabrication of vertically aligned anatase TiO2 nanowires by electrospinning: Preferred architecture for nanostructured solar cells

Abstract

Higher performance is expected in electronic devices that utilize metal oxide semiconductors in vertical architecture owing to the direct and effective electron transport. Producing anatase phase vertical TiO2 nanowires on conductive substrate has been challenging. Herein we demonstrate for the first time not only the facile fabrication of vertical arrays of anatase TiO2 nanowires, but also fabricating the wires by using electrospinning method. Firstly aligned nanofiberous TiO2 ribbons were produced by electrospinning and then erected to vertical nanowires after the post-treatment. As-produced vertical ceramic TiO2 nanowires possessed the area of 0.2 cm2 with wire diameter of 90 ± 30 nm, and height up to 27 μm. This approach can be a better alternative to the currently available methods like hydrothermal synthesis and template assisted fabrication as the diameter, height of the wires, and spacing between the wires can be effectively controlled by this method. With vertical nanowires of anatase phase TiO2 as photoelectrode in dye sensitized solar cells (DSSC), the solar-to-current conversion efficiency (η), short circuit current (Jsc), open circuit voltage (Voc), and fill factor (FF) were measured as 2.87% and 5.71 mA cm−2, 0.782 V, 64.2% respectively.