Controlling of structural ordering and rigidity of β-SiAlON:Eu through chemical cosubstitution to approach narrow-band-emission for light-emitting diodes application
Abstract
Narrow-band green-emitting phosphor β-SiAlON:Eu has been widely used in advanced wide-gamut backlighting de- vices. However, the origins for unusual sharp lines in photoluminescence emission at room temperature and tunable narrow-band- emission tailored by reducing Al-O in β-SiAlON:Eu are still unclear. Here, the presence of sharp-line fine structure in the emission spectra of β-SiAlON:Eu is mainly due to purely electronic transitions (zero phonon lines) and their vibronic repetitions resulted from the multi-microenvironment around Eu2+ ions that has been revealed by relative emission intensity of sharp line depends on excitation wavelength and monotonously increasing decay time. The specific features of the Eu2+ occupying interstitial sites indicate that the effect of crystal field strength can be neglected. Therefore the enhanced rigidity and higher ordering structure of β-SiAlON:Eu with decreasing the substitution of Si–N by Al–O become the main factors in decreasing electron–lattice coupling and reducing inhomo- geneous broadening, favouring the blue-shift and narrow of the emission band, the enhanced thermal stability, as well as the charge state of Eu2+. Our results provide new insights for explaining the reason for narrow-band-emission in β-SiAlON:Eu, which will deliver an impetus for the exploration of phosphors with narrow band and ordering structure.
Citation
Zhang , X , Fang , M-H , Tsai , Y-T , Lazarowska , A , Mahlik , S , Lesniewski , T , Grinberg , M , Pang , W K , Pan , F , Liang , C , Zhou , W , Wang , J , Lee , J-F , Cheng , B-M , Hung , T-L , Chen , Y-Y & Liu , R-S 2017 , ' Controlling of structural ordering and rigidity of β-SiAlON:Eu through chemical cosubstitution to approach narrow-band-emission for light-emitting diodes application ' , Chemistry of Materials , vol. 29 , no. 16 , pp. 6781-6792 . https://doi.org/10.1021/acs.chemmater.7b01697
Publication
Chemistry of Materials
Status
Peer reviewed
ISSN
0897-4756Type
Journal article
Description
The authors are grateful for the financial support of the Ministry of Science and Technology of Taiwan (Contract Nos. MOST 104- 2113-M-002-012-MY3, MOST 104-2119-M-002-027-MY3 and 104-2923-M-002-007-MY3) and Australia Research Council (ARC, FT160100251). The contribution of A. L. was supported by the grant “Preludium” UMO-2014/13/N/ST3/03781 from the National Science Center. The contribution of S. M. was supported by the grant “Iuventus Plus” 0271/IP3/2015/73 from the Ministry of Science and Higher Education. M. G. was supported by Polish National Center for Research and Development with grants no PBS3/A5/48/2015 and PL-TWII/8/2015.Collections
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