Cubic Ba2LaF7:Yb3+/Ln(Ln = Er3+,Ho3+) up-conversion submicron particles controllable synthesis and luminescence properties

In this paper, a co-doped cubic phase submicron particles Ba2LaF7:Yb3+/Ln3+ (Ln = Er3+,Ho3+) up-conversion material were successfully synthesized by hydrothermal method. By adjusting PH, time, temperature, and the amount of sodium citrate during the preparation process, it was possible to analyze and obtain the phase structure, morphology, and up-conversion luminescence characteristics of the particles. Furthermore, the influence of doping concentration on the up-conversion luminescence characteristics was studied using X-ray diffractometer (XRD), scanning electron microscopy (SEM), fluorescence spectroscopy, and other characterization methods. The test results show that, under the conditions of pH = 9 and NaBF4 as the fluorine source, Ba2LaF7:Yb3+/Ln3+ (Ln = Er3+,Ho3+) spherical particles have an average size of 240 nm. Under the excitation of a 980 nm laser-diode (LD) laser, it was found that the material spectrum is mainly composed of strong green and weak red light. When Yb3+ and Er3+ doping concentrations are 18% and 2.5%, Yb3+ and Ho3+ doping concentrations are 18% and 3.5%, respectively, the up-conversion transmittance is the highest. Finally, the possible causes of the fluorescence decay curve of Ba2LaF7:Yb3+/Ln3+ (Ln = Er3+,Ho3+) up-conversion materials were investigated.