Luminescence and creation of electron-hole trapping centers in alkali metal sulfates activated by Pb2+ impurity

Abstract

The nature of the impurity emission and the process of creating intrinsic and impurity electron-hole trapping centers were studied by spectroscopic and thermal activation methods in Na2SO4 - Pb and K2SO4 - Pb phosphors. The combined radiative electronic state is formed from intrinsic SO3−4- SO−4 and impurity Pb+ - SO−4 electron-hole trapping centers in UV-irradiated phosphors with a photon energy of 6.2 eV at 80 K. Emissions of 3.2 eV and 3.6 eV resulting from irradiation with photons with an energy of 6.2 eV are associated with intracenter transitions of 3p1- 1s0 in Pb2+ located in nonequivalent positions of the Na2SO4 lattice.

Keywords

• electron;
• hole
• recombination emission;
• intrinsic emission;
• sulfate;
• excitation