Effects of Sm Co-doping on Luminescent Properties of Sr4Al14O25:M (M=Mn4+, Cr3+) Phosphors

Abstract

The Sr 4 Al 14 O 25 :M and doped Sr 4 Al 14 O 25 :M+Sm 3+ (M=Mn 4+ , Cr 3+) phosphors were synthesized by a solid-state reaction method and their luminescent properties were investigated. The results showed that the co-doping of Sm ions did not change the positions of excitation band and emission band but significantly improved the luminescent properties of Sr 4 Al 14 O 25 :Cr 3+ phosphors; whereas, the emission intensity of Sr 4 Al 14 O 25 :Mn 4+ was reduced remarkably when Sm ions were co-doped. In addtion, a radiative-form energy transfer from Sm 3+ to Cr 3+ was observed for the first time in the Cr, Sm co-doped Sr 4 Al 14 O 25 phosphors. The results indicated that Sm ions could significantly improve the emission intensity of Sr 4 Al 14 O 25 :Cr 3+ , making the Sm 3+ co-doped Sr 4 Al 14 O 25 :Cr 3+ phosphor a promising candidate for the applications in display and solid state lightening.

First-principles calculations to identify key native point defects in Sr4Al14O25

“…The lower limit of allowed µ E F values is set by V O species close to the VBM, i.e. at 0.14 eV for V O (5) . In this dopability domain, i.e.…”

“…For Sr Al antisites, only the substitution of Al 3+ by Sr 2+ may be observed for O-poor atmospheres, while all the Sr 0 Al and Sr −1 Al species may appear under O-rich conditions. For the O-intermediate condition, the ε (0/ − 1) charge transition of the Sr Al(1) , Sr Al(2) , Sr Al(4) and Sr Al (5) defects are lying in the lower part of the µ E F allowed range, while the Sr 0 Al(3) and Sr 0 Al(6) species cannot be created. At q = 0, the lowest DFEs are observed for Al(1) sites, i.e.…”

“…Namely, a deep red emission with potential application in white lightening is observed when Mn 4+ cations are used as activators. [1][2][3][4][5][6][7] In contrast, Ce 3+ dopants induce a blue-green emission. 8,9 Moreover, Mn 4+ ,Tb 3+ co-doped Sr 4 Al 14 O 25 is a thermographic material for temperature imaging, as the emission color strongly changes due to the thermal quenching of the Mn 4+ emission.…”