Preparation and Optimization of Mn2+-Activated Na2ZnGeO4 Phosphors: Insights into Precursor Selection and Microwave-Assisted Solid-State Synthesis

Mn2+-doped phosphors emitting green light have garnered significant interest due to their potential applications in display technologies and solid-state lighting. To facilitate the rapid synthesis of high-performance Mn2+-activated green phosphors, this research optimizes a microwave-assisted solid-state (MASS) method for the preparation of Na2ZnGeO4:Mn2+. Leveraging the unique attributes of the MASS technique, a systematic investigation into the applicability of various Mn-source precursors was conducted. Additionally, the integration of the MASS approach with traditional solid-state reaction (SSR) methods was assessed. The findings indicate that the MASS technique effectively incorporates Mn ions from diverse precursors (including higher oxidation states of manganese) into the crystal lattice, resulting in efficient green emission from Mn2+. Notably, the photoluminescence quantum yield (PLQY) of the sample utilizing MnCO3as the manganese precursor was recorded at 2.67%, whereas the sample synthesized from MnO2exhibited a remarkable PLQY of 17.69%. Moreover, the post-treatment of SSR-derived samples through the MASS process significantly enhanced the PLQY from 0.67% to 8.66%. These results underscore the promise of the MASS method as a novel and efficient synthesis strategy for the rapid and scalable production of Mn2+-doped green luminescent materials.