Synthesis and photoluminescence properties of novel far-red emitting garnet phosphor Y3Ga3MgSi(1-y)GeyO12:Mn4+

In this paper, a novel far-red emitting garnet-structured phosphor, Y₃Ga₃MgSiO₁₂:Mn⁴⁺, was synthesized using the traditional solid-state reaction method. The prepared Y₃Ga₃MgSiO₁₂:Mn⁴⁺ phosphor exhibits a broad excitation band in the range of 250–600 nm and emits bright far-red light in the wavelength range of 630–710 nm, with a peak at 670 nm when excited at 354 nm. The optimal doping concentration of Mn⁴⁺ is approximately x = 0.006. Beyond this concentration, luminescence quenching occurs due to energy transfer between Mn⁴⁺ ions caused by dipole-dipole interactions. The effect of cation substitution on the photoluminescence properties of Y₃Ga₃MgSi_(1-y)Ge_yO₁₂:0.01Mn⁴⁺ phosphors was studied, revealing that the substitution of Ge⁴⁺ ions can systematically influence the luminescence of Mn⁴⁺. The Y₃Ga₃MgSiO₁₂:0.01Mn⁴⁺ phosphor exhibits excellent color purity, and its emission spectrum matches well with the absorption spectra of photosensitive pigments P_R and P_FR. The temperature-dependent emission spectra of Y₃Ga₃MgSi_(1-y)Ge_yO₁₂:0.01Mn⁴⁺ phosphors were studied, and the activation energy was calculated. The substitution of Ge⁴⁺ ions can improve the thermal stability of the samples. These outstanding photoluminescence properties suggest that Y₃Ga₃MgSiO₁₂:Mn⁴⁺ phosphor has application potential in pc-WLEDs and indoor plant cultivation pc-RLEDs. The findings of this work provide ideas for the design of high performance Mn⁴⁺ activated phosphors.