Concentration dependence of luminescence properties in praseodymium and praseodymium/ytterbium-doped lutetium double phosphates

In this paper we present a comparative optical study of praseodymium and praseodymium/ytterbium-doped lutetium double phosphates in the wide spectral range (VUV–IR) and for various concentrations of the activators. The absorption and emission spectra of Na3Lu(PO4)2:Pr3+ and Na3Lu(PO4)2:Pr3+, Yb3+ were measured at room and low temperatures. It was shown that spectroscopic properties of investigated systems strongly depend on the concentration ratio of the Pr3+ and Yb3+ ions.