Synthesis and luminescence properties of color-tunable Ce, Mn co-doped LuAG transparent ceramics by sintering under atmospheric pressure

Herein, Lu3-x-yCexMnyAl5-ySiyO12 transparent ceramics were prepared via a high-temperature solid-state reaction under a flowing O-2 atmosphere and annealed under a H-2-N-2 atmosphere. The structure and luminescence properties of these ceramics have been discussed in detail. Polished transparent ceramics with uniform grains exhibited the highest optical transmittance of 81.9% at 800 nm. After the introduction of Mn2+ into the ceramic, the photoluminescence (PL) spectrum of the Lu2.885Ce0.015Mn0.1Al4.9Si0.1O12 ceramic showed a green emission band centered at 520 nm and a red emission band centered at 582 nm under the 450 nm excitation. These ceramics exhibited excellent luminescence thermal stability, and the quenching temperature of all the ceramics exceeded 200 degrees C. The fluorescence lifetime indicated an efficient energy transfer from Ce3+ to Mn2+, and the highest energy transfer efficiency reached 42.3%. According to the PL spectra and emission decay curves, the energy transferred from Ce3+ to Mn2+ via a non-radiative transition. Via controlling the concentration of the Mn2+-Si4+ ions, the emitted light changed from green to orange and the chromaticity color coordinates shifted from (0.3758, 0.5722) to (0.4594, 0.5093). The light-emitting diode (LED) lamps based on Lu3-x-yAl5-yO12 (LuAG):0.015Ce(3+), yMn(2+), ySi(4+) (y = 0.4, 0.6, 0.8) transparent ceramics exhibited low correlated color temperatures (4238-3534 K) with luminous efficacy in the range of 78.52-55.70 lm/W. Thus, the color-tunable Ce, Mn co-doped LuAG transparent ceramics are promising candidates for white LEDs.

Automated summary

Transparent ceramics Lu3-x-yCexMnyAl5-ySiyO12 were prepared through high-temperature solid-state reaction under a flowing O-2 atmosphere and exhibited excellent optical transmittance and luminescent properties. The color-tunable Ce, Mn co-doped LuAG transparent ceramics showed promising potential as candidates for white LEDs due to their outstanding luminescence thermal stability and efficient energy transfer.