Luminescence and electron spin resonance studies of narrow-band UVB emitting Gd3+ doped Y2SiO5 nanophosphors synthesized by sol-gel method

Abstract Y2SiO5 nanophosphors doped with various Gd3+ ion concentrations were synthesized by citrate-based sol-gel method and investigated through X-ray diffraction (XRD), FTIR, electron spin resonance (ESR) and optical studies. XRD revealed the characteristic peaks of the planes corresponding to a monoclinic phase of a P21/c space group. The XRD analysis using Scherrer's formula showed that the Y2SiO5 crystallites were sized 22 nm. The FTIR spectral analysis of the characteristic vibrational bands of the Y2SiO5 matrix revealed an intense absorption band at 1039 cm−1. The ESR studies revealed the presence of Gd3+ ions in the octahedral locations of the Y2SiO5 matrix. The photoluminescence (PL) excitation spectra disclosed a prominent band at 273 nm, which was selected for excitation of Gd3+:Y2SiO5 nanophosphors. An ultraviolet luminescence emission band was detected at 313 nm due to the 6PJ→8S7/2 transition under 273 nm excitation.