Spectral study on manganese- and silver-doped lithium tetraborate phosphors

Manganese- and silver-doped lithium tetraborate (LTB) single crystal and glassy phosphors with different dopant contents were studied. Optical absorption, steady-state and time-resolved photoluminescence (PhL) techniques were used for spectral characterization of samples. Optical absorption, as well as PhL excitation and emission spectra of LTB:Mn single crystal, revealed that manganese is present only in the form of Mn 2+ions, while in the glassy LTB:Mn simultaneous presence of Mn 2+ and Mn 3+ ions was detected. Optical absorption and PhL spectral characterization of LTB:Ag single crystal showed that only one type of Ag 1+ ions are absorbing and emitting centers while in the LTB:Ag glassy samples the presence of at least two non-equivalent surrounding of Ag 1+ ions was revealed.