Site-Selective Excitation of Ti Ions in Rutile TiO via Anisotropic Intra-Atomic 3d → 3d Transition.

Site-selective excitation (SSE), which is usually realized by tuning the wavelength of absorbed light, is an ideal way to study bond-selective chemistry, analyze the crystal structure, investigate protein conformation, etc., eventually leading to active manipulation of desired processes. Herein, SSE has been explored in (110)-, (100)-, and (011)-faced rutile TiO, a prototypical material in both surface science and photocatalysis fields.

Valence Band of Rutile TiO(110) Investigated by Polarized-Light-Based Angle-Resolved Photoelectron Spectroscopy.

Band structure dictates optical and electronic properties of solids and eventually the efficiency of the semiconductor based solar conversion. Compared to numerous theoretical calculations, the experimentally measured band structure of rutile TiO, a prototypical photocatalytic material, is rare. In this work, the valence band structure of rutile TiO(110) is measured by angle-resolved photoelectron spectroscopy using polarized extreme ultraviolet light.

Anisotropic d-d Transition in Rutile TiO.

The band gap state of TiO, which is dominated by Ti 3d character, is of great relevance to light absorption, electron trapping, charge recombination, and conduction band structure. Despite the importance, the explanation of the excitation from this state is controversial. To this end, the electronic structures of TiO(110) and TiO(011)-(2 × 1) have been systematically measured with two-photon photoemission spectroscopy.