Novel wet-chemical routes to highly structured semiconductor layers for improved efficiency photovoltaic devices.

There is increasing interest in using ZnO as an alternative to TiO₂ in photoelectrochemical (PEC) solar cells that employ high surface area nanostructured substrates. Columnar ZnO films may offer fundamental advantages over nanoporous TiO₂ such as improved electrical transport properties. We have grown perpendicularly orientated ZnO crystallites, on novel ZnO template layers, from aqueous solutions containing a zinc carboxylate salt and hexamethylenetetraamine (HMT). These films provide a high surface area substrate for subsequent overgrowth of semiconductor sensitizer layers of Cu_2−xS and Cu_2−xSe. Films have been characterized by spectroscopic methods (UV-VIS, photoluminescence, PL), microscopy (scanning electron microscopy, SEM) and X-ray diffraction (XRD) methods. [ABSTRACT FROM AUTHOR]