Ba3Y2WO9:Mn4+: A near-UV and yellow-green light excited red phosphor for greenhouse cultivation

Abstract

A novel Mn4+-activated Ba3Y2WO9 phosphor of double perovskite structure has been prepared via high-temperature solid-state reaction method. The phosphor can emit red emission located at ～692 nm, which greatly overlaps with the absorption spectra of chlorophyll and phytochrome in the red light range. the intensest excitation band of the phosphor originating in the O2−→Mn4+ charge transfer and the 4A2g→4T1g of Mn4+ centres at ～367 nm, while the sub intense excitation band formed by 4A2g→4T2g transition is located in the yellow-green light region (～535 nm). The excitation and emission performance of the phosphor indicates its potential application in light-conversion film/glass for greenhouse cultivation since it can convert not only UV but also yellow-green light into red emission. The optimal doping concentration of Mn4+in the Ba3Y2WO9 host is 0.3 mol%, beyond which energy transfer between Mn4+ ions based on d-d interaction results in fluorescence quenching. Besides, the crystal field strength and thermal stability of the sample are also discussed.