Difference of SERS ability from titanium oxide films by Ti3+ self-doping

With the Ti3+ self-doping, the surface-enhanced Raman scattering (SERS) ability of titanium oxide films shows difference. In this paper, the titanium oxide films were fabricated by electron beam evaporation under different oxygen flow. The surface morphology, element composition, optical property and SERS ability were characterized, respectively. The X-ray photoelectron spectroscopy reveals the existence of two different valence states of titanium ion in samples. Both the optical absorption and the bandgap shows difference when various quantities of Ti3+ was doped, which is related to the SERS ability. As a result, the Raman scattering intensity of RhB molecule increases when the number of Ti3+ increases. In conclusion, the SERS ability of titanium oxide films is related to the amount of doped Ti3+ in film, which is valuable to the SERS research.