Investigating the Spectroscopic Performance of Y3Al5O12:Mn4+ Phosphors Co-Doped with Divalent Metal Ions and the Use of Phosphor Film for “Green” Plant Cultivation

The intensity and quality of the artificial light used in “green” plant cultivation greatly affect plant morphogenesis and physiological responses. Light-conversion films based on phosphors that can enable the precise conversion of ultraviolet (UV) radiation into photosynthetically active radiation (i.e., red light) hold great promise for next-generation ecological agriculture. However, conventional red phosphors often suffer from low stability or emit a short-wavelength red light more suitable for display than plant growth, limiting their agricultural applications. Herein, a weather-resistant Mn 4+ -doped yttrium aluminum garnet (YAG:Mn 4+ ) deep red phosphor with a strong emission peak at 672 nm was synthesized. The phosphor’s luminescent properties were optimized by introducing Mg 2+ as a charge compensator, thereby significantly increasing the phosphor’s emission intensity. Detailed photoluminescence and thermal quenching behaviors were investigated through comprehensive spectroscopic analyses. Light-conversion film made of biodegradable polyvinyl alcohol and the prepared phosphors was utilized to intensify the process of cultivating pea seedlings. As a proof of concept, a preliminary study under sunlight with an additional UV lamp demonstrated that treatment with the prepared light-conversion film enhanced the growth of pea seedlings. These improvements can be attributed to the effective conversion of UV radiation, which is useless for plant growth, into beneficial red light. The results demonstrate the potential of YAG:Mn 4+ –Mg 2+ -based phosphor films to improve agricultural productivity and promote eco-friendly cultivation practices.