Luminescence properties of AgTb(WO4)2 doped with Ce3+: Experimental determination of the Stern-Volmer quenching constant

Scheelite-like AgTb(WO4)2 doped Ce3+ were synthesized by ceramic method. Efficient characteristic bands of Tb3+ were observed in AgTb(WO4)2 compounds. However, the presence of Ce3+ quenched the emission band of Tb3+ which can be caused by metal-to-metal charge transfer between Tb3+/Ce3+. The quenching is more efficient at high temperature which can be attributed to more overlaps of wave functions of Ce3+-W6+-Tb3+ at high temperature. The experimental Stern-Volmer quenching rate constant at room temperature and liquid nitrogen temperature were measured as (376±4)·10−3 μs−1 (x content/mol)−1 and (45±4)·10−3 μs−1 (x content/mol)−1 respectively. In excitation spectra, evident blue shift of charge transfer band in the case of liquid nitrogen temperature was observed. In addition, the blue shift of CT band also occurred with increasing concentration of Ce3+. The shifting of charge transfer band can be interesting to the design of solar cells and tunable excitation sources and detectors.