Bright UV-C Phosphors with Excellent Thermal Stability-Y1- xSc x PO4 Solid Solutions

Dmitry Spassky; Andrey Vasil'ev; Vitali Nagirnyi; Irina Kudryavtseva; Dina Deyneko; Ivan Nikiforov; Ildar Kondratyev; Boris Zadneprovski

doi:10.3390/ma15196844

Bright UV-C Phosphors with Excellent Thermal Stability-Y_{1- x}Sc _x PO₄ Solid Solutions

Materials (Basel). 2022 Oct 2;15(19):6844. doi: 10.3390/ma15196844.

Authors

Dmitry Spassky^{1

2}, Andrey Vasil'ev¹, Vitali Nagirnyi², Irina Kudryavtseva², Dina Deyneko^{3

4}, Ivan Nikiforov³, Ildar Kondratyev⁵, Boris Zadneprovski⁶

Affiliations

¹ Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Leninskiye Gory 1-2, 119991 Moscow, Russia.
² Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu, Estonia.
³ Department of Chemistry, Lomonosov Moscow State University, Leninskiye Gory 1-3, 119991 Moscow, Russia.
⁴ Laboratory of Arctic Mineralogy and Material Sciences, Kola Science Centre, Russian Academy of Sciences, 14 Fersman Street, 184209 Apatity, Russia.
⁵ Physics Department, Lomonosov Moscow State University, Leninskiye Gory 1-2, 119991 Moscow, Russia.
⁶ All-Russian Research Institute for Synthesis of Materials, Institutskaya Street 1, 601600 Alexandrov, Russia.

Abstract

The structural and luminescence properties of undoped Y_1-xSc_xPO₄ solid solutions have been studied. An intense thermally stable emission with fast decay (τ_1/e ~ 10^-7 s) and a band position varying from 5.21 to 5.94 eV depending on the Sc/Y ratio is detected and ascribed to the 2p O-3d Sc self-trapped excitons. The quantum yield of the UV-C emission, also depending on the Sc/Y ratio, reaches 34% for the solid solution with x = 0.5 at 300 K. It is shown by a combined analysis of theoretical and experimental data that the formation of Sc clusters occurs in the solid solutions studied. The clusters facilitate the creation of energy wells at the conduction band bottom, which enables deep localization of electronic excitations and the creation of luminescence centers characterized by high quantum yield and thermal stability of the UV-C emission.

Keywords: ScPO4; UV-C phosphor; YPO4; bandgap; energy transfer; luminescence thermal stability; self-trapped exciton luminescence; solid solution.

Abstract

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