Ce/Mn/Cr: (Re,Y)₃Al₅O₁₂ Phosphor Ceramics (Re = Gd, Tb and Lu) for White LED Lighting with Significant Spectral...

In order to attain phosphor ceramics with a high Color-Rendering Index (CRI), samples with the composition of Y_0.997-xRe_xCe_0.003)₃(Al_0.9748 Mn²⁺_0.024Cr³⁺_0.0012)₅O₁₂(Re_x = 0, Gd_0.333, Gd_0.666, Gd_0.997, Tb_0.333, Tb_0.666, Tb_0.997 and Lu_0.997 were prepared by solid-state reaction and vacuum sintering, and exhibited potential for high-quality, solid-state lighting. Doping with Cr³⁺ and Mn²⁺ effectively enhanced the red component of Ce³⁺ spectra through the intense energy transfer from Ce³⁺ ions to Mn²⁺/Cr³⁺ ions. The crystal field splitting of [GdO₈] and [TbO₈] was more extensive than that of [YO₈], causing a massive redshift in the Ce³⁺ emission peaks from 542 to 561 and 595 nm, while [LuO₈] had an opposite effect and caused a blueshift with a peak position at 512 nm. White LED devices incorporating Ce/Mn/Cr: (Gd_0.333Y_0.664)₃Al₅O₁₂ phosphor ceramic exhibited a high CRI of 83.97, highlighting the potential for enhancing the red-light component of white LED lighting.