Impact of Er3+ Concentration on Luminescence in NaLaF4

In this work, NaLaF doped with Er of different concentrations was synthesized. The luminescence spectrum for NaLaF :Er (0.2 mol%) at 489 nm excitation reveals characteristic Er luminescence bands in the green (540 nm), red (660 nm) and infrared (980 nm) spectral regions. The green luminescence band originated from the → transition is the most intensive one in the luminescence spectrum. As the concentration of the activator is increasing, the intensity of all luminescence bands changes significantly. The super-linear increase of the infrared luminescence intensity with increasing Er concentration as well as the quenching of green luminescence at the concentrations exceeding 2 mol% can be attributed to the cross-relaxation process between the activator ions. Darbā pētīta Er fotoluminiscences atkarība no Er koncentrācijas NaLaF matricā. Pieaugot Er koncentrācijai līdz 2mol% luminiscences intensitātes raksturīgajām Er joslām zaļā (540nm), sarkanā (660nm) un infrasarkanajā (980 nm) spektra apgabalā pieaug. Pie Er koncentrācijas virs 2mol% novērojama izteikta zaļās luminiscences koncentrācijas dzēšana un virslineārs infrasarkanās luminiscences joslas pieaugums, kas saistīts ar kross-relaksācijas procesiem starp aktivatora joniem.