Developing narrow-band red-emitting ceramic phosphors with high quantum yield and low thermal quenching is vital for mid to high powder solid state lighting. In this study, a series of (Y0.75Sc0.25)2O3:Eu3+ ceramics were fabricated and their photoluminescence properties were studied. The spectral measurement suggests that the optimal doping concentration of Eu3+ is as high as 14%. The heavily doped samples show strong absorption in the NUV-blue region (particularly 360–420 nm and 460–475 nm), bright red emission dominated by the sharp peak located at 611 nm, CIE chromaticity coordinates close to the NTSC standard value of red emission, and single exponential photoluminescence decay without afterglow. In particular, ((Y0.75Sc0.25)0.86Eu0.14)2O3 ceramic exhibits high QY of 86.9%, high color purity of 96.9%, and low thermal quenching loss of 16% as the temperature increases from 300 to 570 K. The excellent photoluminescence properties highlight the great potential of Eu3+ heavily doped (Y0.75Sc0.25)2O3 red-emitting ceramics as color converters for solid state lighting, which is demonstrated by the outstanding electroluminescence performance of the fabricated red and white LEDs.
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