Enhancing the luminescence of Ba0.2La1.8MgTi0.9W0.1O6: Mn4+ phosphors for plant growth applications via H3BO3 incorporation or cation substitution

The advancement of modern artificial plant cultivation necessitates the development of high-performance far-red-light sources precisely tailored to plant spectral absorption profiles, which is crucial for enhancing crop yield and quality in contemporary agricultural practices. In this study, a cation substitution strategy was implemented by replacing Ba 2+ ions with smaller Ca 2+ cations to induce unit cell contraction. This structural modification reduces the degree of distorted octahedral coordination available for Mn 4+ substitution, effectively suppressing non-radiative transitions. As a result, the optimized phosphor exhibits a threefold enhancement in emission intensity along with significantly improved thermal stability. Furthermore, the incorporation of H 3 BO 3 as a flux agent enhanced crystallinity, synergistically boosting both luminescent performance and thermal stability. The resultant Mn 4+ -activated phosphor achieves a quantum efficiency of 81.2 % with characteristic far-red emission peaking at 708 nm. Fabricated far-red phosphor-converted light-emitting diodes and photoconversion films incorporating this phosphor demonstrate exceptional potential for precision-controlled plant growth modulation.