Preparation of up-converting nano-biphasic calcium phosphate

Abstract

The nano-biphasic calcium phosphate co-doped with 1 mol% Er³⁺ and 5 mol% Yb³⁺ ions was prepared using Pechini's technique. The preparation of the biphasic calcium phosphate showed the removal of fluorine ions from the matrix. The structural properties and morphology of the particles were studied by means of XRD (X-ray powder diffraction), TEM (Transmission Electron Microscopy), and SEM (Scanning Electron Microscopy) techniques. The spectroscopic properties of Ca₁₀(PO₄)₆F₂/Ca₃(PO₄)₂:Er³⁺,Yb³⁺ nano-biphasic calcium phosphate were investigated in detail using emission spectra, power dependence and emission kinetics. This material demonstrated intense green up-conversion depending on laser power. Additionally, the luminescence lifetimes for Er³⁺ ions were calculated from the measured decays. Power dependence of the green and red emissions was found to result from a temperature increase of nano-biphasic calcium phosphate that opens potential applications in theranostics.