White light emission and thermoluminescence studies of Dy3+ -activated hardystonite (Ca2 ZnSi2 O7 ) phosphor.

ABSTRACT

Here, we report the photoluminescence and thermoluminescent properties of Dy-activated Ca2 ZnSi2 O7 phosphors synthesized using the solid-state method. The synthesized phosphors showed hardystonite type structure, and had micron-sized particles. Fourier transform infrared spectroscopy (FTIR) showed the existence of the functional groups and confirmed the formation of phosphor and photoluminescence techniques. The phosphors under excitation at 239 nm exhibited green-yellow emission spectra in the region 481-575 nm corresponding to the 4 F9/2 →6 H15/2 and 4 F9/2 →6 H13/2 transitions of Dy3+ ions. The Commission Internationale de l'Eclairage (CIE) coordinates were achieved to be (0.25, 0.27), which was narrowly close to the white region. Thermoluminescence (TL) glow curve analysis of prepared Dy3+ -activated Ca2 ZnSi2 O7 phosphors were recorded for different ultraviolet (UV) light exposure times and found to have a linear response with dose. The TL glow curves, recorded with various UV exposure times ranging from 5 to 25 min, showed a linear response with dosage. The corresponding kinetic parameters were also calculated using a computerized glow curve deconvolution (CGCD) technique. Activation energy was observed to enhance the increase in the peak temperature and its value was substantially higher for the third peak fitted using CGCD. The obtained results indicated that the synthesized pristine phosphors could be potentially used for lighting, displays, and dosimetric applications.