The influence of the conduction band of BaCl2 on the thermal quenching of the Tm2+ 4f125d1→4f13 and 4f13→4f13 luminescence in orthorhombic BaCl2:Tm2+/3+
Year: 2024
Type: article
Abstract: The positioning of the Tm 2+ 4f 12 5d 1 and 4f 13 energy levels as relative to the conduction band of the orthorhombic BaCl 2 host lattice has been determined. Therefore, the energies of the Tm 2+ 4f 12 5d 1 -and excited 4f 13 -level were retrieved, as relative to the Tm 2+ 4f 13 ground state. In addition, the energy for exciton creation in the orthorhombic BaCl 2 host lattice was established, from which the bandgap energy was determined. This value was found to correspond quite well to known literature values. Furthermore, the Tm 3+ -Cl - charge transfer transition was determined, from which the energy difference between the Tm 2+ 4f 13 ground state and the top of the BaCl 2 valence band was deduced. A host referred binding energy scheme deduced for BaCl 2 :Tm 2+ then showed that the lowest energy Tm 2+ 4f 12 5d 1 -levels are positioned 0.3–0.5 eV below the BaCl 2 conduction band. Room temperature photo-excitation into this level will then most likely result in thermal ionization effects that have an impact on the Tm 2+ 4f 12 5d 1 →4f 13 and 4f 13 →4f 13 luminescence and corresponding quantum yield.
Source: Optical Materials X
Authors: M.P. Plokker, H.T. Hintzen
Institution: Delft University of Technology
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,860
Funder: Technische Universiteit Delft
OpenAlex ID: W4405166016