Luminescence properties of Ce 3+ and/or Mn 2+ activated Ca 10K(PO 4) 7 under ultraviolet and vacuum ultraviolet excitation

Abstract

New Ce 3+ and/or Mn 2+ activated Ca 10K(PO 4) 7 phosphors were prepared by solid-state reaction, and their photoluminescence properties upon ultraviolet and vacuum ultraviolet excitation were investigated. Under 254 nm excitation, a series of Ca 10K(PO 4) 7: xMn 2+ samples exhibit two emission bands at 463 and 650 nm, which could be attributed to oxygen defects and 4T 1– 6A 1 transition of Mn 2+, respectively. And an energy transfer from defects to Mn 2+ has been observed. With the Mn 2+ content increased, the emitting hues of Ca 10K(PO 4) 7:Mn 2+ can range from blue to red. By co-doping Ce 3+ to Ca 10K(PO 4) 7:Mn 2+, the emission intensity of Mn 2+ is strongly enhanced due to an efficient energy transfer by [Ce 3+ → Mn 2+] and [defects → Ce 3+ → Mn 2+]. But under 147 nm excitation, the emission intensity of Mn 2+ in Ca 10K(PO 4) 7:0.25Mn 2+ decreases slightly compared with that in Ca 10K(PO 4) 7:025Mn 2+, 0.1Ce 3+, 0.1K + due to the host sensitization competition between Ce 3+ and Mn 2+.