Luminescence and photo‐thermally stimulated defect creation processes in PbWO4:Mo, La, Y (PWO III) crystals. Issue 10 (14th July 2015)

• Record Type: Journal Article
• Authors: Auffray, E.; Korjik, M.; Laguta, V. V.; Zazubovich, S.
• Is Part Of: Physica status solidi. Volume 252:Issue 10(2015:Oct.)
• Page Start: 2259
• Page End: 2267
• Publication Date: 2015-07-14
• Subjects: Solid state physics -- Periodicals; Solids -- Periodicals; Atomic structure -- Periodicals; 530.41
• DOI: 10.1002/pssb.201552188
• Languages: English
• ISSNs: 0370-1972

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssb201552188-sec-0001" sec-type="section"> <p>Photoluminescence, thermally stimulated luminescence and electron spin resonance are studied for a PbWO<sub>4</sub> crystal grown by the Czochralski method at Bogoroditsk Technical Chemical Plant, Russia from the melt with a precise tuning of the stoichiometry and co‐doped with La<sup>3+</sup>, Y<sup>3+</sup>, and Mo<sup>6+</sup> ions. Photo‐thermally stimulated processes of electron and hole centers creation under selective UV irradiation of the crystal in the 3.5–5.0 eV energy range and 85–205 K temperature range are clarified and the optically created electron and hole centers are identified. The electrons in this crystal are found to be mainly trapped at the (MoO<sub>4</sub>)<sup>2−</sup> groups as well as at the (WO<sub>4</sub>)<sup>2–</sup> groups located close to single La<sup>3+</sup> and Y<sup>3+</sup> ions, producing electron (MoO<sub>4</sub>)<sup>3–</sup>, {(WO<sub>4</sub>)<sup>3–</sup> – La<sup>3+</sup>} and {(WO<sub>4</sub>)<sup>3–</sup> – Y<sup>3+</sup>} centers. The holes are mainly trapped at the regular oxygen ions O<sup>2–</sup> located close to La<sup>3+</sup> and Y<sup>3+</sup> ions associated with lead vacancies, producing the O<sup>−</sup>(I)‐type centers, or to single Mo ions, producing the O<sup>−</sup>(II) centers. No evidence of single‐vacancy‐related centers has been observed. The data obtained indicate a small concentration of single (non‐compensated) oxygen (<italic>V</italic><sub>O</sub>) and lead (<italic>V</italic><sub>Pb</sub>) vacancies as the traps for electrons and holes, respectively, which explains more favorable scintillation characteristics of the PbWO<sub>4</sub>:Mo, La, Y crystal as compared with the earlier studied PbWO<sub>4</sub>:Mo, La and PbWO<sub>4</sub>:Mo, Y crystals.</p> </sec> </abstract>