Synthesis, structural and optical properties of Fe-doped nanocrystalline SnO₂

In the present study we have fabricated Fe doped SnO₂ nanoparticles co-precipitation method. These samples were characterized by thermal gravimetric and differential thermal analysis, X-ray diffraction (XRD) analysis, field emission-scanning electron microscopy (FE-SEM), energy dispersive studies by X-rays technique, transmission electron microscopy,selected area electron diffraction studies, Ultraviolet–Visible spectroscopy, fourier transform infrared (FTIR) spectroscopy, Raman and photoluminescence (PL) spectroscopicmeasurements. XRD analysis revealed the single phase rutile tetragonal structure of all samples. These results werefurther confirmed by Raman and FTIR studies. Crystallite size was observed to vary from 17 to 8 nm as the Fe content increased from 0 to 4 mol%, suggesting the prevention of crystal growth with Fe doping. It was evident from the absorption spectra that the absorbance increases with the dopant concentration. Optical band gap was estimated by using Tauc relation whichdecreases with the increase in Fe content confirmingthe size reduction as a result of Fe doping. Raman spectroscopic measurementsshowed thatthe broadening of intense peak observed at 630 cm⁻¹ with Fe doping, indicating that the Fe ions are substituted at the Sn sites in SnO₂ lattice. Room temperature PL spectra revealed that luminescent emission intensity increases with Fe concentration.