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First‐principles and crystal‐field calculations of the electronic and optical properties of two novel red phosphors Rb 2 HfF 6 :Mn 4+ and Cs 2 HfF 6 :Mn 4+
Author(s) -
Liu DongXu,
Ma ChongGeng,
Hu PeiWen,
Li Zuo,
Tian Ya,
Su Ping,
Brik Mikhail G.,
Srivastava Alok M.,
Tanabe Setsuhisa
Publication year - 2018
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.15406
Subject(s) - phosphor , excitation , point reflection , chemistry , crystal field theory , phonon , electronic structure , symmetry (geometry) , crystal (programming language) , field (mathematics) , emission spectrum , intensity (physics) , spectral line , atomic physics , molecular physics , analytical chemistry (journal) , materials science , condensed matter physics , physics , optics , computational chemistry , optoelectronics , ion , organic chemistry , geometry , mathematics , quantum mechanics , astronomy , chromatography , computer science , programming language , pure mathematics
The electronic, structural, and optical properties of 2 red phosphors, Rb 2 HfF 6 :Mn 4+ and Cs 2 HfF 6 :Mn 4+ , are evaluated using the first‐principles and crystal field theory methods. The calculated trigonal splitting of the Mn 4+ orbital triplets perfectly matches the experimental excitation spectra. The structural and electronic properties of the mixed compound RbCsHfF 6 are also studied theoretically. In the mixed compound, the inversion center symmetry around the Hf site is removed. This symmetry lowering may result in an increase in the Mn 4+ 2 E→ 4 A 2 zero phonon line ( ZPL ) intensity, which is very weak in the 2 end members. This finding may be of interest for increasing the phosphor luminosity. It is believed that such a mechanism of local site symmetry lowering by preparing solid solutions may be used for other systems as well, to gain ZPL intensity and perhaps to minimize thermal losses, eventually leading to improved phosphor materials.