Behaviour quantification of Sm³⁺ in borotellurite glass phosphors for warm-colour illumination

Lighting in unconventional environments is closely related to eye health and circadian rhythms, making it essential for warm-colour light sources to align with technological advancements in solid-state lighting. Herein, warm light in spectral region over 550 nm is realised in Sm³⁺ doped multicomponent borotellurite (MBT-Sm) glass phosphors as colour converters for LEDs/LDs and their luminescent behaviours are quantified in detail. MBT-Sm glass phosphors standout for their high transparency and the large absorption/emission cross-section, with high quantum efficiency of 84.1 % and quantum yield of 19.15 % under violet LED excitation, and a high luminous flux of 3.33 lm under 50 mW laser. Remarkably, it not only possesses superior colour performance with the correlated colour temperature below 2000 K and colour purity up to 99.8 %, but also shows excellent heat resistance of luminescence. MBT-Sm glass phosphors show promising applications as colour conversion materials in innovative lighting technology.