Impact on the structural and photophysical properties of TiO₂ films owing to Li implantation

We investigated here the effect of defects on the structural and photophysical properties of TiO₂ films implanted with Li ions with fluences from 1 × 10¹⁴ to 1 × 10¹⁵ ions/cm². All the films showed tetragonal anatase structure but higher angle shift of the (101) peak of implanted films confirms Li doping in Ti site. This result is also supported by our X-Ray photoelectron spectroscopy study. The results also indicated that with an increase in Li ion fluence, formation of defects like oxygen vacancy and/or Ti³⁺ species increases in implanted samples. This is also supported by theoretical “stopping and range of ions in matter” (SRIM) simulations. The introduction of oxygen vacancy-Ti³⁺ defects act as recombination centers which gives rise to significant change in emission properties and decrease the photoresponse properties of the TiO₂ films after Li implantation.