Surface termination effect on the photocatalysis on atomically controlled SrTiO3(001) surface

We have demonstrated a surface termination effect on the photodecomposition of a monolayer (ML) pentacene film on the SrTiO3(001) single crystal surface. To prepare SrO-terminated SrTiO3(001), a SrO thin film was deposited on TiO2-terminated SrTiO3(001) by a laser molecular beam epitaxy method. The coverage of the SrO layer was precisely controlled utilizing in-situ reflection high energy electron diffraction (RHEED) intensity monitoring. The photodecomposition of the pentacene film was directly observed and quantitatively analyzed by an atomic force microscope (AFM). The 1 ML SrO was enough to completely suppress the photodecomposition of the pentacene film on SrTiO3(001). The electron transfer process from the bulk to electron scavengers such as adsorbed O2 molecules at the surface depended greatly on the choice of the surface termination layer of SrTiO3(001).