Investigation of optical transitions and electrical properties in LaVO3/SrTiO3 heterostructure.

LaVO 3 (LVO) is particularly interesting due to its optical band gap of around 1.1 eV, which is close to the one of silicon (1.12 eV) and can be an interesting light-absorbing material for photovoltaic and photocatalytic devices. In this context, we investigated the optical and transport properties of LaVO 3 grown on SrTiO 3 (STO) heterostructures under various growth conditions. The study of the optical properties shows significant variation in optical absorption with oxygen partial pressure during the deposition. Moreover, from the electrical point of view, the LaVO 3 /SrTiO 3 deposited at low oxygen pressure reveals a metallic behavior with high mobility conduction. However, those grown at high oxygen pressure turn into an insulator showing a metal–insulator transition. Interestingly, the optical measurements combined with electrical sheet resistance confirm that the metallic behavior originates from the diffusion of oxygen vacancies within the SrTiO 3 substrate during the deposition process of LaVO 3 layers. These results open fascinating prospects to use LaVO 3 as an efficient optical absorber for solar irradiance, whereas, the SrTiO 3 substrate could be integrated as a bottom electrode to facilitate the collection of charge carriers. As a result, LaVO 3 /SrTiO 3 system shows promising properties and might be potentially interesting for future integration in photovoltaic and photocatalytic applications. [ABSTRACT FROM AUTHOR]