ZnO Nanorod-arrays as photo-(Electro)chemical materials: Strategies designed to overcome the material's natural limitations

The urgent need for clean and storable energy drives many currently topical areas of materials research. Among the many materials under investigation zinc oxide is one of the most studied in relation to its use in photo-(electro)chemical applications. This study aims to give an overview of some of the main challenges associated with the use of zinc oxide for these applications: the high density of intrinsic defects which can lead to fast recombination, low visible light absorption and the occurrence of photo-corrosion. Employing simple low-temperature solution based methods; it is shown how defect-engineering can be used to increase the photo-electrochemical performance and how doping can strongly increase the visible light absorption of zinc oxide nanorod-arrays. Furthermore the deposition of ultra-thin titanium dioxide layers using atomic layer deposition is investigated as possible route for the protection of zinc oxide against photo-corrosion.