| Abstrakt: |
Herein, the self-reduction behavior of manganese (Mn) in Mg2SnO4 (MSO) host lattices prepared by using the solid-state reaction technique in air atmosphere is reported. Excited by 282 nm, only the emission of Mn2+ is seen, and the observed results are confirmed by theoretical calculation based on the density functional theory. Noteworthy, with the codoping of Li+, the self-reduction process of Mn is suppressed, leading to the coexistence of Mn2+ and Mn4+ in MSO host lattices along with the multicolor emissions. For the suppressed self-reduction behavior, possible hypotheses are proposed to elucidate the corresponding mechanisms. Furthermore, benefiting from the different thermal quenching behaviors of Mn2+ and Mn4+, ratiometric optical thermometers with high sensitivity of 6.59% K-1 are designed. Moreover, the prepared phosphors possess a good green afterglow phenomenon, in which their trap depth are 0.71 and 0.91 eV. In addition, via using the designed phosphors, applications in anti-counterfeiting, fingerprint identification, and optical information storage are also realized. [ABSTRACT FROM AUTHOR] |
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