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Improving LED Efficiency with the New Polymorph β‐Ca 1− x Sr x AlSiN 3 :Eu 2+
Author(s) -
Fiedler Tim,
Dirksmeyer Stephanie,
Seibald Markus,
Hummel Franziska,
Peschke Simon,
Achrainer Gina M.,
Bichler Daniel
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201904329
Subject(s) - phosphor , orthorhombic crystal system , light emitting diode , full width at half maximum , diode , materials science , white light , analytical chemistry (journal) , chemistry , crystal structure , crystallography , mineralogy , optoelectronics , chromatography
Innovative materials for phosphor‐converted white light‐emitting diodes (pc‐LEDs) are much sought after due to the huge potential of the LED technology to reduce energy consumption worldwide. One of the main levers for further improvements are the conversion phosphors. The system Ca 1− x Sr x AlSiN 3 :Eu 2+ currently provides one of the most important red‐emitting phosphors for pc‐LEDs. We report the discovery of the new polymorph β‐Ca 1− x Sr x AlSiN 3 :Eu 2+ which allows for significant improvements to LED efficacies. It crystallizes in the orthorhombic space group Pbcn with lattice parameters a= 982.43(10) pm, b= 575.2(1) pm and c= 516.12(5) pm. Compared to α‐Ca 1− x Sr x AlSiN 3 :Eu 2+ , its emission shows a significantly reduced spectral full‐width at half maximum (FWHM). With that, we demonstrated 3 % efficacy increase for white light‐emitting pc‐LEDs. The new polymorph can easily be industrialised, because the synthesis works on the same equipment as α‐Ca 1− x Sr x AlSiN 3 :Eu 2+ .