Hollow sphere TiO₂: Synthesis and its application for dye-sensitized solar cells

The architecture of semiconductor oxides as the core photoanodes in the dye-sensitized solar cells affecting the energy conversion of the dye-sensitized solar cells (DSSC) has been a slightly neglected parameter. Herein, we study that the morphology of hollow sphere (HS) TiO 2 as the semiconductor photoanode of DSSC has proven to result in the power conversion efficiency (PCE) higher than the solid sphere of TiO 2 , and other morphology such as nanotube, nanowire, and nanorod. Affecting the photocurrent density (Jsc) and PCE, efficient electron transfer was achieved in HS TiO 2 . The percentage of PCE of DSSC using HS TiO 2 semiconductor is also influenced by physical properties such as particle size and shell thickness, which influence the dye-loading capacity, the rate of electron transfer, and the scattering effects in visible light harvesting. This review discusses the synthesis and characterization of HS TiO 2 from two different synthesis pathways, the one-pot and two-step synthesis, and the modification of HS TiO 2 to improve the efficiency of DSSC.