Modifications of structural and optical properties of nanophase BaWO4 phosphors: Dose dependent effect of high energy electron beam irradiation

Highlights: • BaWO₄ nanoparticles were synthesised by direct chemical precipitation method. • First report for the dose dependent effect of EB irradiation on the structure and optical properties of BaWO₄. • PL and CIE chromaticity studies reveal that BaWO₄ phosphors are useful to construct NUV light excited blue LEDs. • EB irradiation is an effective tool for enhancing the PL properties of the BaWO₄ nanoparticles. The present work reports dose dependent influence of 8 MeV electron beam irradiation on the structural and optical properties of BaWO₄ nanoparticles fabricated by chemical precipitation route. The synthesized materials were calcined at 400 °C for 3 h to get well defined nanocrystalline particles. The calcined materials were irradiated by 8 MeV electron beams of different doses and studied the influence of irradiation on the structural and optical properties of BaWO₄ nanoparticles using various characterization tools. The structural studies revealed modifications of lattice parameters a and c, unit cell volume, d spacing, crystallite size, micro-strain, and peak shift for major peaks of X-ray diffraction patterns of the electron irradiated samples. The electron irradiation also results some defects in the crystal lattice of BaWO₄ nanocrystals upon electron beam irradiation. Scanning electron microscopic images demonstrated mesoporous behaviour of the BaWO₄ materials. The optical studies established that optical bandgap and intensity of photoluminescence emission can be modified by using electron irradiation technique for potential applications in electronics. Photoluminescence emission properties of BaWO₄ phosphors suggest that they are useful for the construction of near ultraviolet light excited blue light emitting diodes. Results explored from the present work constitute the first report for the dose-dependent influence of electron beam irradiation on the structure, optical absorption and photoluminescence properties of BaWO₄ nanoparticles.