Strongly enhanced photoluminescence and X-ray excited optical luminescence of the hydrothermally crystallized (Sr,Mn)5(PO4)3(F,Cl) nanorods by composition modulating

Abstract

The development of emitting materials that present both photoluminescence (PL) and X-ray excited optical luminescence has recently been attracting rising research interest for visualization applications. We introduced in this study the hydrothermally crystallized (Sr1-xMnx)5(PO4)3F1-yCly (x = 0–0.05, y = 0–0.40) nanorods with favorable PL and X-ray excited optical luminescence properties after composition modulating. The effects of solution pH and Cl− incorporation on structure and morphology of the products were firstly unveiled. (Sr1-xMnx)5(PO4)3F gives green emission at ∼548 nm (4T1(4G) → 6A1(6S)) under either 402 nm excitation or X-ray irradiation, and the optimal PL and X-ray excited optical luminescence were observed at x = 0.03. The replacement of F− by larger Cl− led to the generation of an amount of Frenkel defects (the dislocated F− and anion vacancies VF.) along the c-axis, benefit from which the (Sr0.97Mn0.03)5(PO4)3F1-yCly samples present enhanced PL and X-ray excited optical luminescence intensities by factors of 1.6 and 7.4, respectively, and the corresponding optimal y values are determined to be 0.20 and 0.30. Fluorescence decay analysis found steadily shortened fluorescent lifetime for Mn2+ at higher Mn2+ and Cl− concentrations, and the underlying mechanism was discussed. The (Sr,Mn)5(PO4)3(F,Cl) apatite material, with enhanced PL and X-ray excited optical luminescence, may find novel applications for both lighting and scintillating.