Incorporation of dopants in semiconductors is commonly used to modify the optical response and improve the efficiency of related devices. A physical understanding with elemental and local sensitivity of the electron excitation and trapping channels which follow photoexcitation is a prerequisite for knowledge-based materials design. By using high-resolution x-ray absorption methods we show that, in V-doped Ti O 2 nanoparticles, subband-gap visible light absorption is predominantly due to excitation of electrons from V ions to defective and long-lived Ti sites. We thus identify an element-specific photoexcitation channel.
American Physical Society
7 Jul 2017
Volume: 96 Issue: 4 Pages: 045303
Physical Review B