Atomic species identification at the (101) anatase surface by simultaneous scanning tunnelling and atomic force microscopy

作者：Stetsovych Oleksandr; Todorovic Milica; Shimizu Tomoko K; Moreno Cesar; Ryan James William; Leon Carmen Perez; Sagisaka Keisuke; Palomares Emilio; Matolin Vladimir; Fujita Daisuke; Perez Ruben^*; Custance Oscar

来源：Nature Communications, 2015, 6(1): 7265.

DOI：10.1038/ncomms8265

Anatase is a pivotal material in devices for energy-harvesting applications and catalysis. Methods for the accurate characterization of this reducible oxide at the atomic scale are critical in the exploration of outstanding properties for technological developments. Here we combine atomic force microscopy (AFM) and scanning tunnelling microscopy (STM), supported by first-principles calculations, for the simultaneous imaging and unambiguous identification of atomic species at the (101) anatase surface. We demonstrate that dynamic AFM-STM operation allows atomic resolution imaging within the material's band gap. Based on key distinguishing features extracted from calculations and experiments, we identify candidates for the most common surface defects. Our results pave the way for the understanding of surface processes, like adsorption of metal dopants and photoactive molecules, that are fundamental for the catalytic and photovoltaic applications of anatase, and demonstrate the potential of dynamic AFM-STM for the characterization of wide band gap materials.

• 出版日期2015-6