CW EPR investigation of red-emitting CaS:Eu phosphors: rationalization of local electronic structure

Spencer, Jacob, Merrikin, Danielle, Pope, Simon ORCID: https://orcid.org/0000-0001-9110-9711, Morgan, David ORCID: https://orcid.org/0000-0002-6571-5731, Carthey, Nicholas and Murphy, Damien ORCID: https://orcid.org/0000-0002-5941-4879 2020. CW EPR investigation of red-emitting CaS:Eu phosphors: rationalization of local electronic structure. Advanced Optical Materials 8 (22) , 2001241. 10.1002/adom.202001241

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (2MB) | Preview

Abstract

A series of commercial and prepared CaS:Eu2+ rare earth activated phosphors are investigated following different post‐synthetic treatments. A number of species directly related to the function of the material are characterized using electron paramagnetic resonance (EPR) spectroscopy. Isolated Eu2+ sites are identified and associated with the substitutional doping for Ca2+ in the lattice which are responsible for the 645 nm emission of interest. Another inactive Eu2+ site based within a “EuO” type phase aggregated on the surface of the material is also identified, as well as competitive F+ center defects that are known to reduce emission from the Eu2+ sites. Intrinsic Mn2+ impurities are identified and used as local order probes to determine changes in ordering and symmetry upon cryo‐milling and heating treatments of the samples. X‐ray photoelectron (XPS) and photoluminescence (PL) spectroscopies are also conducted to complement the local structure observations. The reported data is useful in understanding how the nature of the lattice affects ground state electronic structure of functional defective sites, for the development of efficient and selective materials.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Chemistry
Publisher:	Wiley
ISSN:	2195-1071
Date of First Compliant Deposit:	24 September 2020
Date of Acceptance:	25 August 2020
Last Modified:	17 Aug 2023 07:41
URI:	https://orca.cardiff.ac.uk/id/eprint/135085

Citation Data

Cited 2 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item