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A series of Bi 4 Si 3 O 12 :Dy 3+ phosphor have been synthesized via conventional solid-state reaction method and its luminescence properties were investigated as near cool white light emitting and long afterglow phosphor. Crystal structure and phase structure characterization is determined using X-ray diffraction (XRD), SEM and EDS. Rietveld structural refinement and XRD confirms that prepared sample exhibit pure cubic structure [space group I-43d]. Photoluminescence spectra of both doped and undoped Bi 4 Si 3 O 12 phosphor were efficiently excited in the range of 200-450 nm, and prepared phosphor under 272 nm excitation exhibit three emission peaks located at 463 nm(blue), 482 nm(blue) and 576 nm (yellow) corresponding to 3 P 1  →  1 S 0 , 4 F 9/2  →  6 H 15/2 and 4 F 9/2  →  6 H 13/2 transitions. Characteristic emission peaks of Dy 3 + centered at 482 nm and 576 nm were assigned for white light emission. The calculated Commission Internationale de I’Eclairage (CIE) chromaticity confirms that with Dy 3+ doping, the luminescence co-ordinates of Bi 4 Si 3 O 12 phosphor shift to near white( x  = 0.316, y  = 0.358) region which is close to commercial pc-LED (Blue LED + YAG:Ce 3+ ) ( x  = 0.320, y  = 0.320) co-ordinates. Computation of correlated color temperature 6184 K endorses that prepared phosphor is cool in nature and can be served as white light emitting phosphor. Comparative thermoluminescence study of UV and γ-irradiated Bi 4 Si 3 O 12 :Dy 3+ phosphor is performed for the dosimetry application. TL intensity is recorded maximum at 30 min under UV irradiation (256 nm), and for γ irradiation, it was recorded at 10 kGy dose rate. γ-irradiated Bi 4 Si 3 O 12 :Dy 3+ phosphor TL study is reported for the first time at different dose rate and concentration for high dosimetry application. The defect characteristic is examined, Trap depths and other kinetic parameters are also evaluated by Chen’s peak shape method. Decay and fading measurement under UV/γ irradiation are performed to examine the long after glow properties of prepared samples. TL emission spectrum studies are also performed.

Calcium barium orthosilicate (CaBaSiO4) phosphors having different concentrations of Dy3+ were prepared by solid-state reaction method, and phase structure of the sample was identified by X-ray diffraction (XRD) characterization. It is observed that the XRD pattern matched well with JCPDS file No. 48-0210. Thermoluminescence (TL) of the UV-irradiated (254 nm) samples was recorded using routine TL set-up Nucleonix TLD reader with constant heating rate 5 °C s−1. It is found that the sample containing 1 mol% of Dy3+ and exposed for 27 min gives optimum TL intensity at 130.14 °C and shows single TL glow peak. It order to examine the effect of charge compensator ion, Li+ ions are introduced and it is found the incorporation of charge compensator enhances the TL output. Samples having 1 mol% of Dy3+ and 6 mol% of Li+ exposed for 30 min to UV exposure show maximum intensity at 118 °C. It is also observed that temperature corresponding to TL peak varies with varying Li concentration (ranging from 105.76 to 123.88 °C). Samples having 1 mol% of Dy3+ and 6 mol% of Li+ exposed for 30 min to UV exposure were selected for further studies, such as activation energy, order of kinetics and frequency factor, and all these parameters were evaluated using peak shape method.

Sr 2 MgSi 2 O 7 :Eu 3+ and Sr 2 MgSi 2 O 7 :Eu 3+ , R + (R +  = Li + , Na + and K + ) phosphors were prepared by conventional solid state reaction method. The crystal structures of synthesized phosphors were an akermanite type structure which belongs to the tetragonal crystallography. The thermoluminescence kinetic parameters such as activation energy, order of kinetics and frequency factor was calculated by peak shape method. In this work, the orange-red emission originated from the 5 D 0 – 7 F J (J = 0, 1, 2, 3, 4) transitions of Eu 3+ ions could clearly be observed after samples were excited at 395 nm. Decay graph indicate that these phosphors also contain the fast and slow decay process. Mechanoluminescence intensity of prepared Sr 2 MgSi 2 O 7 :Eu 3+ and Sr 2 MgSi 2 O 7 :Eu 3+ , R + (R +  = Li + , Na + and K + ) phosphors were increases linearly with the increasing impact velocity of moving piston (load). CIE color chromaticity diagram confirm that the prepared phosphors would emit orange-red color. Thus the present investigation indicating that this phosphor may be a potential candidate for stress sensors. The dopant R + (R +  = Li + , Na + and K + ) as charge compensator in Sr 2 MgSi 2 O 7 :Eu 3+ can further enhance luminescence intensity, and the emission intensity of Sr 2 MgSi 2 O 7 :Eu 3+ doping Li + is higher than that of Na + or K + .

A series of dysprosium (Dy3+) doped barium ortho-silicate (Ba2SiO4) phosphors were synthesized by conventional Solid State reaction technique. In order to find out the phase purity and crystal structure, characterization of the prepared powder samples was done by X-ray diffraction (XRD) method. FTIR method confirms the presence of all elemental compositions. Photoluminescence (PL) properties were studied. The PL spectra was observed to study the effect of concentration of Dy3+ ion and it is found that the prepared phosphors show two strong emission peaks in the blue and yellow region at 478 nm and 573 nm, respectively, when excited by the near-ultraviolet (UV) of wavelength 348 nm. The critical distance between the Dy3+ ions was calculated using Blasse's equation. Effect of monovalent ion K+ was examined as a charge compensator ion and observed that co-doping of charge compensator ion enhances the luminescence intensity. Chromaticity coordinates of the phosphor are found near to white light region, which confirms their applicability in solid state lighting applications; especially in white-LEDs.

In this research paper, we present a study on the preparation and spectroscopic properties of Dy 3+ -doped calcium barium ortho-silicate (CaBaSiO 4 ) phosphor. The phosphors were synthesized using the solid-state reaction route. The obtained powders underwent characterization through X-ray diffraction (XRD) and Furrier transform infrared (FTIR), confirming phase purity and the presence of functional groups, respectively. Energy-dispersive X-ray (EDX) reveals the elemental composition of the material under examination. The spectroscopic properties of Dy 3+  in CaBaSiO 4 phosphor were investigated through emission and excitation spectra analysis. The emission spectra exhibit two peaks in the blue region at 482 nm and in the yellow region at 574 nm under UV excitation with a wavelength of 349 nm. Both emission peaks are attributed to the 4 F 9/2  →  6 H 15/2 and 4 F 9/2  →  6 H 13/2 characteristic transitions of the Dy 3 +  ion. The critical distance was calculated using the Blasse equation. Monovalent ions were added to the host as charge compensator ions to enhance the luminescence intensity. The CIE chromaticity coordinates were determined from the emission spectra, affirming that the CaBaSiO 4 phosphor is a suitable candidate for solid-state lighting applications, particularly in w–LEDs.

A series of dysprosium (Dy 3+ ) doped barium ortho-silicate (Ba 2 SiO 4 ) phosphors were synthesized by conventional Solid State reaction technique. In order to find out the phase purity and crystal structure, characterization of the prepared powder samples was done by X-ray diffraction (XRD) method. FTIR method confirms the presence of all elemental compositions. Photoluminescence (PL) properties were studied. The PL spectra was observed to study the effect of concentration of Dy 3+ ion and it is found that the prepared phosphors show two strong emission peaks in the blue and yellow region at 478 nm and 573 nm, respectively, when excited by the near-ultraviolet (UV) of wavelength 348 nm. The critical distance between the Dy 3+ ions was calculated using Blasse’s equation. Effect of monovalent ion K + was examined as a charge compensator ion and observed that co-doping of charge compensator ion enhances the luminescence intensity. Chromaticity coordinates of the phosphor are found near to white light region, which confirms their applicability in solid state lighting applications; especially in white-LEDs.

Sr2MgSi2O7:Eu3+ and Sr2MgSi2O7:Eu3+, R+ (R+ = Li+, Na+ and K+) phosphors were prepared by conventional solid state reaction method. The crystal structures of synthesized phosphors were an akermanite type structure which belongs to the tetragonal crystallography. The thermoluminescence kinetic parameters such as activation energy, order of kinetics and frequency factor was calculated by peak shape method. In this work, the orange-red emission originated from the 5D0-7FJ (J = 0, 1, 2, 3, 4) transitions of Eu3+ ions could clearly be observed after samples were excited at 395 nm. Decay graph indicate that these phosphors also contain the fast and slow decay process. Mechanoluminescence intensity of prepared Sr2MgSi2O7:Eu3+ and Sr2MgSi2O7:Eu3+, R+ (R+ = Li+, Na+ and K+) phosphors were increases linearly with the increasing impact velocity of moving piston (load). CIE color chromaticity diagram confirm that the prepared phosphors would emit orange-red color. Thus the present investigation indicating that this phosphor may be a potential candidate for stress sensors. The dopant R+ (R+ = Li+, Na+ and K+) as charge compensator in Sr2MgSi2O7:Eu3+ can further enhance luminescence intensity, and the emission intensity of Sr2MgSi2O7:Eu3+ doping Li+ is higher than that of Na+ or K+.

Sr sub(2)MgSi sub(2)O sub(7):Eu super(3+) and Sr sub(2)MgSi sub(2)O sub(7 ):Eu super(3+), R super(+) (R super(+) = Li super(+), Na super(+) and K super(+)) phosphors were prepared by conventional solid state reaction method. The crystal structures of synthesized phosphors were an akermanite type structure which belongs to the tetragonal crystallography. The thermoluminescence kinetic parameters such as activation energy, order of kinetics and frequency factor was calculated by peak shape method. In this work, the orange-red emission originated from the super(5)D sub(0)- super(7)F sub(J) (J = 0, 1, 2, 3, 4) transitions of Eu super(3+) ions could clearly be observed after samples were excited at 395 nm. Decay graph indicate that these phosphors also contain the fast and slow decay process. Mechanoluminescence intensity of prepared Sr sub(2)MgSi sub(2)O sub(7 ):Eu super(3+) and Sr sub(2)MgSi sub(2)O sub(7 ):Eu super(3+), R super(+) (R super(+) = Li super(+), Na super(+) and K super(+)) phosphors were increases linearly with the increasing impact velocity of moving piston (load). CIE color chromaticity diagram confirm that the prepared phosphors would emit orange-red color. Thus the present investigation indicating that this phosphor may be a potential candidate for stress sensors. The dopant R super(+) (R super(+) = Li super(+), Na super(+) and K super(+)) as charge compensator in Sr sub(2)MgSi sub(2)O sub(7 ):Eu super(3+) can further enhance luminescence intensity, and the emission intensity of Sr sub(2)MgSi sub(2)O sub(7 ):Eu super(3+) doping Li super(+) is higher than that of Na super(+) or K super(+).