Photoluminescence properties of Yb2+-doped Ba0.75Al11O17.25 green phosphor ceramic

Abstract

Yb2+-doped Ba0.75Al11O17.25 green phosphor ceramics have been synthesized by spark plasma sintering. Under the excitation of blue light at 405 nm, the ceramics present green light at 535 nm, the emission intensity is the highest when the doping concentration is 1 at. %, and the transmittance can reach 71% at 800 nm. The temperature-dependent photoluminescence spectra of fluorescent ceramics in the range of 24–494 K have been measured. When the temperature increased from 24 to 284 K, the luminous intensity dropped to 75% of that at 24 K, while the luminescence intensity at 414 K can still reach 42% of the luminescence intensity at room temperature, and the thermal stability has been analyzed according to the coordination structure diagram. The thermal conductivity of Yb2+-doped Ba0.75Al11O17.25 green phosphor ceramics at room temperature is 4.32 W/(m K), which is very promising for white LEDs.