Photoluminescence and thermolumineseence properties of tricalcium phosphate phosphors doped with dysprosium and europium

The suitability of calcium phosphate crystals for thermoluminescence dosimetry (TLD) applications is investigated, owing to their equivalence to bone mineral. The alpha and beta phases of tricalcium phosphate (TCP) were synthesized through wet precipitation and high temperature solid state routes and doped with Dy and Eu. The photoluminescence and thermolumineseence studies of the phosphors have been carried out. The TL properties were found to be highly dependent on the method of preparation of the material. Eu doping gave good PL emission, whereas Dy doping was more efficient in TL emission. beta-TCP was found to be less TL sensitive than alpha-TCP, yet it was identified as a better phosphor material owing to its better fading characteristics. The dependence of TL of beta-TCP: Dy on the energy and dose of radiation, and on the doping concentration were studied. The TL intensity was observed to fade exponentially during a storage period of 20 days, but it stabilized at 70% of the initial value after 30 days. The optimum doping concentration was found to be 0.5 mol %.