Optimisation of zinc oxide nanorods for use in dye sensitised solar cells

Abstract

Zinc oxide nanorods were fabricated via a low temperature hydrothermal method on fluorine doped tin oxide (FTO) substrates. The concentrations of hexamethylenetetramine (HMT) and polyethyleneimine (PEI) were optimised to give nanorods with an aspect ratio of ～110. Post-growth thermal annealing and nitrogen plasma treatment led to significant enhancement of the UV emission peak (380 nm) and suppression of the deep level emission peak (600 nm). Although the post-growth treatments did not appear to affect the crystallinity of the ZnO nanorods, the efficiency of dye sensitised solar cells constructed following the post-growth thermal treatments saw a decrease in efficiency.