Oxygen vacancy content drives self-reduction and anti-thermal quenching

Abstract

Oxygen vacancies formed during the sample synthesis induce self-reduction and anti-TQ in air, and the contents can be increased in a reducing atmosphere to lead to stronger photoluminescent performances.

Achieving highly thermostable red emission in singly Mn2+-doped BaXP2O7 (X = Mg/Zn) via self-reduction

“…31) and LiZnPO 4 :Mn 2+ . 32 The manganese ions can be stabilized in several valence states in solids. It is reasonable to design a Mn 2+ -activated phosphor with high thermal resistance in a rigid network structure by taking advantage of the self-reduction phenomenon and a related localized charge defect.…”

Structural confinement-induced highly efficient deep-red emission and negative thermal quenching performance in Mn4+-activated Ca7Mg2Ga6−yAlyO18:Mn4+ phosphors

“…54 In contrast, a negative TQ was relatively rarely observed for Mn 4+ -doped oxide phosphors and only a few examples have been documented as far as we know, such as Sr 2 Ca 0.9 La 0.1 WO 6 :Mn 4+ 55 and Ba 2 CaWO 6 :Mn 4+ . 56 Negative TQ observed for rare-earth-, 57,58 Bi 3+ -, 59 and Mn 2+ -activated 60,61 phosphors are usually attributed to the energy compensation stemming from energy transfer from the lattice defects to the emitting centres at elevated temperatures. However, recent studies on Mn 4+ -doped fluorides have unravelled that the negative TQ is caused by an intrinsic effect, i.e.…”

Anti-thermal quenching phosphors based on the new phosphate host Ca3.6In3.6(PO4)6

“…The TL peak of C 1− x IP:0.03Dy 3+ is at around 348 K, and its depth of the trap energy level was calculated as 0.15 eV using the Urbach formula . 57 One can believe that these lattice defects form a shallow trap level between the conduction and valence band, then the trap level traps and releases electrons under the thermal stimulus.…”