Multi-step hydrothermally synthesized TiO2 nanoforests and its application to dye-sensitized solar cells

► Synthesize large surface area TiO2 nanoforests (TNF) by multi-step hydrothermal process. ► TNF consists of trunks (nanorods) and branches (nanowires). ► TNF offer both large surface area and high carrier transportation rate. ► Enable a high efficiency dye-sensitized solar cell (DSSC). ► 3.93% conversion efficiency with a 5.1 micron high nanoforest.