Luminescence properties of tricalcium phosphate doped with dysprosium

Tricalcium phosphate having effective atomic number Z(eff) = 15.785, equivalent to that of bones was studied for its thermoluminescence (TL) and photoluminescence (PL) properties. Different samples with varied concentrations of the dopant Dy3+ (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mol %) were synthesized by the chemical coprecipitation technique. Phase and compound confirmations were done using X-Ray Diffraction (XRD) and the phosphors' crystallite size was calculated using Scherrer's formula which was found to range between 27 run and 49 nm. The surface morphological study was done using Field Emission-Scanning Electron Microscopy (FE-SEM). Other characterization techniques used for compound confirmation included Energy Dispersive X-Ray Spectroscopy (EDX) and Fourier TranSform Infrared Spectroscopy (FTIR). Samples were further irradiated by gamma rays (emitted from Co-60) with dose varying from 10 Gy to 5 kGy in order to study their n, properties. Concentration optimization of the given phosphor was done in terms of its TL intensity and was found to be 0.5 mol %. The TL dose response of the phosphor was linear over a wide range of dose (10 Gy-3 kGy). Deconvolution was performed on the glow curve for 10 Gy dose, giving six peaks (at 127 degrees, 153 degrees, 185 degrees, 218 degrees, 313 degrees and 335 degrees C) suggesting the presence of six different types of traps. Other characteristics of the TL material i.e. repeatability and fading were also studied. Overall, the phosphor showed promising results for its utility in n, dosimetry. In addition to the TL, PL further confirmed the presence of dopant in the phosphor. Moreover, the dopant concentration was optimized in terms of the nanophosphor's PL intensity. The Commission International de I'Eclairage (CIE) was used to calculate chromaticity coordinates, colour rendering index and colour temperature in order to investigate the phosphor's application in white LEDs.