Influence of Mn(2+) and Eu(3+) Concentration on Photoluminescence and Thermal Stability Properties in Eu(3+)-Activated ZnMoO(4) Red Phosphor Materials

The integration of trivalent europium ion (Eu(3+))-doped zinc molybdate (ZnMoO(4)) as red phosphors in next-generation solid-state lighting (SSL) is impeded by their extended electron lifetime and suboptimal thermal stability. To overcome these limitations, we propose a co-doping approach by incorporating Mn(2+) and Eu(3+) in ZnMoO(4), aiming to improve thermal reversibility and reduce the lifetime of electron transitions. A series of Eu(3+)-doped ZnMoO(4) and Mn(2+)/Eu(3+)-co-doped ZnMoO(4) phosphor materials were synthesized via the conventional sol–gel method, and their photoluminescence properties were compared under high-temperature conditions. Experimental results indicate that the introduction of Mn(2+) into Eu(3+)-doped ZnMoO(4) leads to a decrease in quantum efficiency and electron lifetime, primarily attributed to defects within the crystal lattice and energy transfer from Eu(3+) to Mn(2+), resulting in enhanced non-radiative transitions. However, the addition of a small quantity of Mn(2+) remarkably improves the thermal stability and reversibility of the phosphors. Consequently, this co-doping strategy presents a promising avenue for expanding the application possibilities of phosphor materials, particularly for high-power SSL applications subjected to elevated temperatures. Hence, Eu(3+)-only doped samples are well-suited for lighting applications due to their high IQE and excellent thermal stability. Conversely, Eu(3+)/Mn(2+)-co-doped samples show promise in applications that require a shorter electron lifetime and good reversibility.