Equivalent chemical substitution in double–double perovskite-type ALaLiTeO₆:Mn⁴⁺ (A = Ba²⁺, Sr²⁺, Ca²⁺) phosphors enabling wide range crystal field strength regulation and efficient far-red emission

Abstract

Mn4+-activated phosphors have shown wide perspective applications in phosphor-converted white light-emitting diodes (pc-WLEDs) and pc-LEDs used in illumination and indoor plant cultivation, respectively. Recently, double perovskites A2B′B″O6 with tunable crystal...

Structure and photoluminescence of Mn2+/4+-activated doubly ordered spinel Mg4(Ga/Al)SbO8: site-selective Al3+-to-Ga3+ substitution enabling Mn4+ accumulation, excellent anti-thermal quenching of Mn2+ green emission, and optical thermometry

“…It is well known that deep-red emitting Mn 4+ ions favor octahedral sites and their emission wavelengths depend on the strength of the Mn 4+ -O 2− covalent bonding, that is, stronger Mn 4+ -O 2− covalent bonding usually leads to a longer emission wavelength. 54,55 Hence, the 666 nm emission should be attributed to Mn 4+ emitters residing on the larger Mg1 and Mg2 sites, whereas the 712 nm emission should be ascribed to Mn 4+ ions distributed on the smaller Sb1 and Sb2 sites.…”

Insights into luminescence thermal quenching of Mn4+-doped BaLa(Na/Li)(W/Te)O6 double perovskite red phosphors

“…18,19 It has been reported that the substitution of Ca/Sr/Ba cations allows the improvement of the luminescence thermal stability of ALaLiWO 6 20 and ALaLiTeO 6 . 21 The main luminescence properties of Mn 4+ doped BaLaLiTeO 6 and BaLaLiWO 6 were earlier reported to be have prospects for plant cultivation technologies. 22,23 Meanwhile, a good thermal stability has been documented for Mn 4+ doped BaLaLiTeO 6 .…”

Achieving high-sensitivity dual-mode optical thermometry via phonon-assisted cross-relaxation in a double-perovskite structured up-conversion phosphor

“…In particular, the double perovskite structure of ALaLiTeO 6 (A = Ca, Sr, and Ba) has received widespread attention as a matrix for luminescent materials. [28][29][30] In 2014, S. K. Sali et al for the first time synthesized a double perovskite-type compound BaA'LaTeO 6 (A′ = Na, K, and Rb) and determined its crystal structure using Rietveld analysis and neutron diffraction data. 31 In 2017, G. Subodh et al synthesized the B-site ordered double perovskite ALaLiTeO 6 (A = Ba and Sr) and investigated the vibrating phonon modes for the first time.…”