Synthesis of Bi3+ and Gd3+ doped ZnB2O4 for evaluation as potential materials in luminescent display applications

• ZnB2O4:Bi3+ is an effective purplish blue phosphor.
• ZnB2O4:Gd3+ is an effective ultraviolet phosphor.
• This work indicates that ZnB2O4 is a promising host for display applications.

A series of Bi3+ and Gd3+ doped ZnB2O4 phosphors were synthesized with solid state reaction technique. X-ray diffraction technique was employed to study the structure of prepared samples. Excitation and emission spectra were recorded to investigate the luminescence properties of phosphors. The doping of Bi3+ or Gd3+ with a small amount (no more than 3 mol%) does not change the structure of prepared samples remarkably. Bi3+ in ZnB2O4 can emit intense broad-band purplish blue light peaking at 428 nm under the excitation of a broad-band peaking at 329 nm. The optimal doping concentration of Bi3+ is experimentally ascertained to be 0.5 mol%. The decay time of Bi3+ in ZnB2O4 changes from 0.88 to 1.69 ms. Gd3+ in ZnB2O4 can be excited with 254 nm ultraviolet light and yield intense 312 nm emission. The optimal doping concentration of Gd3+ is experimentally ascertained to be 5 mol%. The decay time of Gd3+ in ZnB2O4 changes from 0.42 to 1.36 ms.