Hydrothermal synthesis of 3D hierarchical flower‐like CuGaO 2 with high surface area for dye‐sensitised solar cell

Abstract

CuGaO2 has been receiving much attention due to its potential as photocathode instead of NiO for p-type dye sensitised solar cells (p-DSSCs). The improvement in the photovoltaic performance of such devices also depends on the increase of the efficient dye loading by significant enhanced specific surface areas. This work reports for the first time the fabrication of the three-dimensional (3D) hierarchical flower-like CuGaO2 nanostructures in a high uniformity by a facile one-step hydrothermal synthesis. The growth mechanism and the effects of the reaction parameters (time and reducing agent) on the formation of the 3D hierarchical flower-like CuGaO2 nanostructures were investigated in detailed. It is significantly to note that the prepared 3D hierarchical flower-like CuGaO2 nanostructures exhibit the highest specific surface areas reported (60 m2/g with ethylene glycol). Due to the efficient dye loading by high specific surface areas, the performance of p-DSSCs based on delafossite CuGaO2 is enhanced. Thereby, based on the optical investigation, electrochemical impedance measurement and Mott–Schottky plots, the improved performance can be attributed to high loading of the dye molecules, the enhanced light-scattering and the reduced interface recombination.