Adjusting luminescence properties of ZnAlO:Mn(Mn), Li phosphors through cation substitution.

ZnAlO with a typical spinel structure is highly expected to be a novel rare-earth-free ion-activated oxide phosphor with red emission, which holds high actual meaning for advancing phosphor-converted light-emitting diode (pc-LED) lighting. Among the rare-earth-free activators, Mn ions have emerged as one of the most promising activators. Considering the price advantage of MnCO generating Mn ions and the charge compensation effect potentially obtaining Mn ions from Mn ions, this research delves into a collection of ZnAlO:Mn(Mn), x Li (x = 0%-40%) phosphors with Li as co-dopant and MnCO as Mn dopant source prepared by a high temperature solid-state reaction method. The lattice structure was investigated using X-ray diffraction (XRD), photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopy. Results suggest a relatively high probability of Li ions occupying Zn lattice sites. Furthermore, Li ion doping was assuredly found to facilitate the oxidization of Mn to Mn, leading to a shift of luminescence peak from 516 to 656 nm. An intriguing phenomenon that the emission color changed with the Li doping content was also observed. Meanwhile, the luminescence intensity and quantum yield (QY) at different temperatures, as well as the relevant thermal quenching mechanism, were determined and elucidated detailedly.