Luminescent phosphors are photoluminescent materials, typically crystalline inorganic hosts doped with activator ions, that absorb energy and re-emit it as light, usually in the visible spectral range, through radiative transitions within localized luminescence centers ^[1]. The host lattice provides the structural and electronic framework, while small concentrations of activator ions—such as rare-earth or transition-metal ions—introduce discrete energy levels within the band gap that capture excitation energy and relax radiatively by emitting a photon of characteristic wavelength; co-dopants may act as sensitizers that transfer absorbed energy to the emitting center ^[2]. A phosphor is distinguished from a generic luminescent material by its deliberate engineering of activator and sensitizer centers in a stable crystalline host to produce efficient, color-controlled light emission, and its behavior is governed by the energy-level structure of the luminescence centers and by energy transfer between them rather than by band-to-band recombination ^[1]. The emission color and efficiency depend on the choice of host and activator, the concentration of the luminescence centers, and non-radiative loss pathways, so that the material is defined by its ability to convert excitation into narrow-band visible light through these impurity-induced centers ^[2]. Its defining feature is controlled light emission via dopant luminescence centers in a crystalline host ^[3].