Mixed Substitution in P‐Doped Anatase TiO 2 Probed by XPS and DFT

• Published in: physica status solidi (b) Vol. 255; no. 4
• Main Authors: Korotin, Michael A., Boukhvalov, Danil. W., Gavrilov, Nikolay V., Kim, Sang S., Cholakh, Seif O., Kurmaev, Ernst Z.
• Format: Journal Article
• Language: English
• Published: 01-04-2018
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.201700477

The investigation of the electronic structure of P‐ion implanted TiO
2
thin films (
E
 = 30 keV,
D
 = 1 × 10
17
 cm
−2
) with anatase structure is performed by X‐ray photoelectron spectroscopy (XPS) measurements (core levels and valence bands) and first‐principles density functional theory (DFT) calculations. It is found that the XPS P 2p‐spectra reveal the presence of two signals at 134.2 and 130.3 eV which can be attributed to the formation of P–O (with P
5+
ions) and P–Ti (with P
3−
ions) bonds, respectively. This means that both cationic (P → Ti) and anionic (P → O) substitution take place in P‐ion implanted anatase thin films. This conclusion is confirmed by DFT calculations which show that the XPS valence band structure of P:TiO
2
can be reproduced only under mixed substitution. The presence of two kinds of phosphorus ions (P
5+
and P
3−
) in ion‐implanted TiO
2
can be useful for developing new multifunctional advanced materials with configurable properties for a wide range of applications.