Reflectance Measurements on Single Crystals of PbFCl, PbFBr, and PbBr₂

Abstract

The reflectance spectra of single crystals of PbFCl and PbFBr are measured between 2.8 and 6.5 eV a t 84 and 295 K. The absorption spectra are calculated by Kramers-Kronig transformation. Peaks a t 4.55 and 5.13 eV in the absorption spectra of PbFBr and PbFCI, respect,ively, are attributed to cation exciton transitions. In the reflectance spectra of vacuum-cleaved single crystals of PbBr,, which are measured a t 84 K with different polarization directions, a new fine structure is observed. An interpretation is given based on an ionic model. Es werden die Reflexionsspektren von PbFCl-und PbFBr-Einkristallen zwischen

Luminescence spectra of PbFCl single crystal under the excitation of synchrotron radiation VUV–UV

“…From the reflection and excitation spectra of PbFCl, the cation exciton absorption peaking at 247 nm was observed. Therefore, the observed UV emission band peaking at 325 nm in PbFCl at 20 K originates from the cation exciton emission, which is also in agreement with what Eijkelenkamp predicted [14].…”

Growth by Bridgman method and luminescence properties of Na:PbFCl crystal

“…However, only few articles on its photoluminescence at low temperatures, reflectivity as well as ionic conductivity have been published [5][6][7][8][9]. As a promising crystal in neutrino detector little practical application was found for PbFCl [10].…”

Self-trapped states and related luminescence inPbCl2crystals

“…Excitons in PbBr 2 crystals, which belong to the same crystallographic group 20 with PbCl 2 and have similar electronic-band structures, 12,21,22,23 undergo uncommon relaxation; 24 they spontaneously dissociate and relax into spatially-separated STEL's and STH's. The recent ESR study 11 supports the relaxed state of excitons structurally.…”