Radioluminescence spectra of PWO crystals (co)doped by Ba

Formation of absorption and emission centres in PbWO 4 surface layers induced by mechanical processing

“…Further significant increase of the scintillation efficiency was reached by codoping the PWO:Mo crystals with Nb or Ta [9,10], with Sb and Cd [11], or with Nb and Ba [12]. It was also found [12] that the GL intensity can be significantly enhanced by shifting the PWO-melt stoichiometry to the surplus of W. Similar result is obtained due to inner stress induced by substitution of Pb 2+ ions for 12% larger Ba 2+ ions. In this paper we study the effect of inner stress in the surface layers of PWO samples resulting from brushing and polishing.…”

“…It was found that the Mo doping can enhance several times the green radioluminescence (RL) intensity of PWO crystals at room temperature (RT) [5][6][7][8]. Further significant increase of the scintillation efficiency was reached by codoping the PWO:Mo crystals with Nb or Ta [9,10], with Sb and Cd [11], or with Nb and Ba [12]. It was also found [12] that the GL intensity can be significantly enhanced by shifting the PWO-melt stoichiometry to the surplus of W. Similar result is obtained due to inner stress induced by substitution of Pb 2+ ions for 12% larger Ba 2+ ions.…”

Influence of non‐stoichiometry and doping on scintillating response of PbWO 4 crystals

“…This paper presents scintillation response measurements of PWO crystals grown from non-stoichiometric melts, undoped or doped by (Ba, Mo) ions. For samples of this type, the radioluminescence intensities have been found to be by nearly one order of magnitude higher than those of the stoichiometric PWO crystals [12].…”

“…more suitable to obtain higher scintillation efficiency. Furthermore, recent study on Ba-doped (Mo-free) PWO indicated possible lower occurrence of harmful shallow trapping states [12], which are responsible for the mentioned slow decay components. The presented results indicate that WO 3 -based green emission centres are the most efficient if the initial melt stoichiometry PbO/WO 3 = 49/51.…”

“…% of Mo instead of W). No similar favourable effect was observed under Ba co-doping where both the blue and green emission bands were observed (detailed description of Ba co-doping influence was given in [12]). On PWO 206 crystal with both the Ba (600 ppm PbO replaced by BaO) and Mo co-dopants the highest light yield was obtained reaching ≈ 10 % of that of BGO.…”