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)GeyO12:0.01Mn(4+) phosphors was studied, revealing that the substitution of Ge4+ ions can systematically influence the luminescence of Mn4+. The Y3Ga3MgSiO12:0.01Mn(4+) 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)GeyO12:0.01Mn(4+) 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.