Anomalous Photoresponse in a Reduced Metal-Semiconductor Hybrid of Nickel and Titanium Oxide

Eutectic NiTiO${}_3$-TiO${}_2$ samples and their H${}_2$ reduced Ni-TiO${}_2$ samples, where high aspect ratio TiO${}_2$ nanostructures are axially decorated with nodular Ni globules, are thoroughly explored to understand their effect in photo-response. We show that by employing this novel eutectic architecture, effectively exploiting the nano-structuring process along with the chosen material properties, the overall efficiency of the ensuing photoactive device is improved. We also show the competing photo-driven and photothermal-driven carrier mechanisms to define the total photo-response of the system. Additionally, the ability to function self-powered poses this approach as a potential strategy for achieving efficient photodetectors.