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 Na 3 Lu(PO 4 ) 2 :Pr 3+ and Na 3 Lu(PO 4 ) 2 :Pr 3+ , Yb 3+ were measured at room and low temperatures. It was shown that spectroscopic properties of investigated systems strongly depend on the concentration ratio of the Pr 3+ and Yb 3+ ions.