Effect of Si4+/Gd3+ doping on luminescence properties of orangish-red light-emitting phosphors of KBaBP2O8:Eu3+

A series of Si4+ or Gd3+ doped KBa0.9BP2O8:0.1Eu(3+) phosphors emitting orangish-red light were successfully synthesized via a conventional high-temperature solid-state method in air atmosphere. The crystal structure and luminescence properties of the phosphors were characterized. The effects of calcination temperature and different ions (Si4+ or Gd3+) co-doping amount on the crystal structure and spectra properties of the phosphors were investigated. The excitation spectra includes a series of spikes in 310-500 nm with the maximum excitation peak of wavelength at 394 nm that matches with the near ultraviolet (UV) LED chips. Under the near UV excitation at 394 nm, the maximum and the sub-strong emission peak appears orange light at 594 nm and red light at 614 nm, which belongs to D-5(0) -> F-7(1) and D-5(0) -> F-7(2) transition of Eu3+, respectively. The results indicate Si4+ or Gd3+ have no obvious influence on the emission peak positions of phosphors, but leads to the change of R/O value. Furthermore, doping Si4+ or Gd3+ both can enhance the luminous intensity of phosphors.