A Facile Synthesis of Granular ZnO Nanostructures for Dye-Sensitized Solar Cells

摘要

Granular ZnO nanostructures of single-crystalline wurtzite hexagonal phases were synthesized by a facile and low-cost chemical method in aqueous condition. The average size of ZnO nanograin increased with reflux time, and it significantly affected the open circuit potential (V_(oc)) while the short circuit current density (J_(sc)) was not changed much. The overall energy conversion efficiency was 1.82% with the smaller grain size of ca. 250 nm when it was used as photoelectrode of DSSCs. The positive shifting of the Fermi energy (E_F) and low density of surface states (DOS) were consistent with the reduction of the recombination of excited electron with electrolyte for smaller grains.