Journal of Luminescence 97 (2002) 198–204 Luminescence of CsPbCl 3 microcrystals dispersed in PbCl 2 :Cs crystals studied under high-energy excitation A. Voloshinovskii a, *, S. Myagkota a , A. Gloskovskii a , S. Zazubovich b a Physical Dept., Ivan Franko National University of Lviv, 8 Kirila i Mefodiya Str., 79005 Lviv, Ukraine b Institute of Physics, University of Tartu, Riia Str. 142, 51014 Tartu, Estonia Received 16 February 2001; received in revised form 25 September 2001; accepted 9 November 2001 Abstract Luminescence spectral and kinetic characteristics have been studied under the synchrotron excitation in the energy range of 4–20 eV for CsPbCl 3 microcrystals dispersed in a PbCl 2 crystal matrix. In the luminescence decay kinetics of the CsPbCl 3 microcrystals, different components have been recorded and connected with the direct excitation of the microcrystals and reabsorption of the self-trapped exciton emission of a PbCl 2 matrix. The decrease of the luminescence decay time of the CsPbCl 3 microcrystals as compared with that characteristic of a CsPbCl 3 single crystal may be caused by the quantum size effect. r 2002 Elsevier Science B.V. All rights reserved. PACS: 78.55; 71.35; 71.55 Keywords: Microcrystals; Energy transfer; Decay time; CsPbCl 3 1. Introduction The microcrystals of CsPbCl 3 dispersed in a CsCl matrix were produced and investigated in Refs. [1,2]. It was shown that CsPbCl 3 micro- crystals have an intense luminescence of free excitons with a short decay time (t f o0:5ns). This is important in view of possible applications of these systems for the registration of high-energy radiation in the nanosecond time interval [1–4]. CsPbCl 3 -like microcrystals are created in CsCl:Pb (C Pb ¼ 0:521mol%) crystals after long- time (t ¼ 102100h) high-temperature (T ¼ 18022201C) annealing [1,2]. Such thermal treat- ment of a CsCl:Pb crystal leads to the activation of anion and cation vacancies motion resulting in changes in the neighborhood of a Pb 2+ ion in a CsCl matrix from eight-fold to six-fold coordina- tion. Such reconstruction leads to the creation of a CsPbCl 3 molecule. A tendency of lead centers to aggregate leads to a local concentration of CsPbCl 3 clusters of molecular type that automa- tically leads to the creation of, at first, a nano- and afterwards a CsPbCl 3 -like microcrystal, dispersed in a CsCl matrix. Such a production mechanism of CsPbCl 3 -like microcrystals differs from the aggre- gate process in NaCl:Pb and KCl:Ag crystals where coordinational compounds like Na m Pb n Cl p *Corresponding author. Tel.: +380-322-794-366; fax: +380- 322-741-323. E-mail address: glos@bigfoot.com (A. Voloshinovskii). 0022-2313/02/$-see front matter r 2002 Elsevier Science B.V. All rights reserved. PII:S0022-2313(02)00224-7