C ions irradiation induced defects analysis and effects on optical properties of TiO₂ Nanoparticles

In this research work, low atomic number (Z) carbon ions (C⁺) were used to treat titanium oxide nanoparticles (TiO₂-NPs) and tune their optical properties. 8 MeV C⁺ were irradiated on TiO₂-NPs at different fluences in the ranges of 2.5×10¹⁵to1×10¹⁶ions/cm² to separately study their defects production and the effect on the bandgap. The C⁺ ion treated samples were investigated using multiple techniques such as XRD, TEM, RAMAN and PL, which confirmed increment of defects were direct proportional to the C⁺ fluences. The increment of defects has resulted in the bandgap reduction from 3.3 eV to 2.9 eV. Theoretical calculations using VASP by implementing density functional theory has produced comparable result. The stability of the structure after induced vacancies has been simulated and confirmed. The incorporation defects by bombardment with low Z ion could be an effective way to tune the bandgap of nanomaterials and improve its optical properties can be used in a wide variety of applications.