Synchrotron and laser excitation of luminescence in PbWO4:Tb crystals at different temperatures

Abstract

The effect of temperature on the spectral luminescence characteristics of PbWO 4 :Tb 3+ crystals with synchrotron and laser excitation is studied. If PbWO 4 :Tb 3+ is excited by synchrotron radiation with λ = 88 nm at 300 K, a faint recombination luminescence of the impurity terbium is observed against the matrix luminescence. When the temperature is reduced to 8 K, the luminescence intensity of PbWO 4 :Tb 3+ increases by roughly an order of magnitude and the characteristic luminescence of the unactivated crystal is observed. Excitation of PbWO 4 :Tb 3+ by a nitrogen laser at 300 K leads to the appearance of emission from Tb 3+ ions. At 90 K, a faint matrix luminescence is observed in addition to the activator emission. The formation of the luminescence excitation spectra for wavelengths of 60-320 nm is analyzed and the nature of the emission bands is discussed.

Low temperature luminescence and scintillation characteristics of SrWO4 crystal

“…The produced electrons and holes after thermalized formed excitons. When the temperature is lowered from 300 to 10 K, the probability of bonding of isolated electrons and holes to an exciton increases, which subsequently increases the emission peak intensity, since the mean free path of electrons and holes in the lattice matrix decreases and the effective radius of the recombination sphere increases with the decrease of temperature [20,21]. The emission peak around 510 nm at 10 K is consistent with the observation of Nikl et al [18] at 5 K. However, we do not observe a narrower central peak surrounded by two shoulders under X-ray and laser excitations as reported in Ref.…”

Investigation of the quenching mechanisms of Tb3+ doped scheelites

“…The break up of the closed shell condition by this valence excitation involves a considerable lattice relaxation. This strong electron-lattice coupling makes trapping of the electronic excitation possible, resulting in a self-trapped exciton (STE) which will largely influence the luminescence and energy transfer properties of the material [32,39,43,44]. Taking this self-trapped exciton into account, the observed thermal quenching in the undoped sample can be explained as follows.…”