A study of optical properties and site preference of Bi3+/Eu3+ co-doped CaLa4Si3O13 red-emitting phosphors for w-LED applications
Eu3+ ions are commonly employed as emitting centres for red phosphors, which suffer from the small absorption cross-sections. In this work, Bi3+ ions are used to sensitize Eu3+ ions in CaLa4Si3O13 host as an attempt to enhance the Eu3+ emission. The site preference of Bi3+ ions is investigated in de...
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Veröffentlicht in: | Journal of luminescence 2020-02, Vol.218, p.116821, Article 116821 |
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Sprache: | eng |
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Zusammenfassung: | Eu3+ ions are commonly employed as emitting centres for red phosphors, which suffer from the small absorption cross-sections. In this work, Bi3+ ions are used to sensitize Eu3+ ions in CaLa4Si3O13 host as an attempt to enhance the Eu3+ emission. The site preference of Bi3+ ions is investigated in detail. The emission peak at 400 and 430 nm can be ascribed to the Bi3+ in La2 and La1 sites, respectively. The reduction of emission intensity and the shortened lifetime of Bi3+ ions suggest that efficient energy transfer from Bi3+ to Eu3+ ions. Moreover, the Bi3+ ions in the La1 sites are confirmed to be more efficient sensitizers for Eu3+ ions owing to the more significant spectral overlap than the Bi3+ ions in the La2 sites. The thermal stability of the synthesized phosphors is superior or comparable with other reported Bi3+/Eu3+ co-doped phosphors, which is not affected by the site preference of Bi3+ ions. The results suggest that Bi3+ ions are efficient sensitizers for Eu3+ ions and the prepared phosphors can be potentially employed as red-emitting component for w-LED applications.
Synopsis: Intense red emission is obtained by sensitizing Eu3+ with Bi3+ ions from different La sites in CaLa4Si3O13 phosphors. [Display omitted]
•Bi3+ ions are employed to sensitize Eu3+ ions to achieve intense red emission.•The site preference of Bi3+ ions is investigated in detail.•Bi3+ ions in the La1 sites are more efficient sensitizers for Eu3+ ions.•The synthesized phosphors exhibit excellent thermal stability. |
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ISSN: | 0022-2313 1872-7883 |
DOI: | 10.1016/j.jlumin.2019.116821 |