The team prepared silver-decorated ZnO nanorod arrays on polyethylene terephthalate (PET) substrates via low-temperature hydrothermal growth followed by electron beam evaporation of silver. The short circuit current density (JSC) and the photo-electron conversion efficiency (PCE) were largely improved for the silver-decorated ZnO nanorod arrays on bent substrates compared with those on flat ones. Maximum values for JSC and PCE were achieved when the silver film thickness and substrate bending radius were 10 nm and 6.0 mm, respectively.

Multiple reflections

To fully understand the reasons behind the result, the researchers carried out systematic studies on the morphologies, structures and optical properties of silver-decorated ZnO nanorod arrays on a bent substrate. It was found that at a combination of silver film thickness=10 nm and bending radius=6.0 mm , the silver-decorated ZnO nanorod arrays were able to trap and absorb the most light. The team attributes these enhanced capabilities to the multiple reflections from the bent substrate, and the plasmonic effect of the silver film.

A full description of the study can be found in the journal Nanotechnology.