Silicon based mos structures with a TiO₂ layer grown by atomic layer deposition for solar fuel generation

In our contribution we have examined the properties of Si photoanodes covered by TiO₂ and Ni thin films. The paper presents the results of electrical measurements of MOS photoanodes with SiO₂ and TiO₂ dielectric layers annealed at different temperatures in the forming gas. Annealing at 400 °C leads to the highest photovoltaic response, which was due to both the low defect state density at the interface and indirect tunnelling of photo-generated holes via insulator-to-semiconductor interface traps. Annealing in the forming gas at a temperature above 400 °C brings about a low interface quality resulting in a negligible photovoltaic response. Based on this study, the post-deposition annealing in at 400 °C results in the best photo-electrochemical response. (authors)