Mechanisms for Enhancing Luminescence Yield in KBr Crystals under the Influence of Low-Temperature Uniaxial Elastic Deformation

• Published in: Crystals (Basel) Vol. 14; no. 8; p. 698
• Main Authors: Shunkeyev, Kuanyshbek, Sagimbayeva, Shynar, Ubaev, Zhiger, Kenzhebayeva, Adelya
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01-08-2024
• Subjects: Anion exchanging; Charge exchange; Crystal lattices; Crystallography; Crystals; Elastic deformation; Excitation spectra; Excitons; high-purity KBr crystal; Investigations; ionic crystal; Low temperature; Luminescence; Luminescence quenching; Radiation; Raw materials; self-trapped exciton; Single crystals; Temperature; uniaxial deformation; X-ray luminescence
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst14080698

This study investigates the radiative relaxation of electronic excitations through luminescence spectroscopy techniques applied to high-purity KBr crystals subjected to low-temperature (85 K) uniaxial deformation along the and crystallographic directions. Results demonstrate that the most significant enhancement in the intensity of σ-(4.42 eV) and π-(2.3 eV) luminescence from self-trapped excitons in KBr crystals occurs with elastic deformation along the direction, aligning with the axis of the hole component of the anion self-trapped exciton. Deformation-induced changes in X-ray, tunneling, and thermally stimulated luminescence spectra reveal a new band, denoted as Ex, peaking at approximately 3.58 eV, attributed to tunneling charge exchange between the F’- and VK-centers in their ground state.