Abstract
The Eu2+-doped mixed alkaline metal strontium borohydride chlorides ASr(BH4)3-xClx (A = K, Rb, Cs) and Eu2+-doped strontium borohydride chloride Sr(BH4)2-xClx have been prepared by mechanochemical synthesis. Intense blue photoluminescence for Sr(BH4)2-xClx (λem= 457 nm) and cyan photoluminescence for the perovskite-type mixed alkaline metal strontium borohydride chlorides ASr(BH4)3-xClx (A = K, Rb, Cs) (λem = 490 nm) is already observable after short milling times. Temperature dependent luminescence measurements reveal an appreciable blue shift with increasing temperature for all ASr(BH4)3-xClx (A = K, Rb, Cs) until 500 K. This extremely large shift, caused by structural relaxation, as well as the vibrationally induced emission band broadening can serve as a sensitive response signal for temperature sensing, and this unique behavior has, to the best of our knowledge, not been reported in any Eu2+ doped phosphor so far. Additionally, bright luminescence, high quantum efficiencies, and very low thermal quenching of these Eu2+-doped borohydrides show that such host materials could serve in solid state lighting applications.
Original language | English |
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Article number | 31 |
Pages (from-to) | 8957-8968 |
Journal | Chemistry of Materials |
DOIs | |
Publication status | Published - 7 Oct 2019 |
Funding
The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript. This research was supported by a Liebig fellowship including doctoral fellowship of the Fonds der Chemischen Industrie (FCI), Grant no. Li 197/02, the German Research Foundation (DFG, KU 3427/4-1), and the Bavarian-French Academy Center for a Mobility aid (Az. FK03_2017). M.S., B.V., and A.M. acknowledge funding from the EU-FET-Open project nanoTBtech (Grant Agreement No. 801305). The authors declare no competing financial interest.