Luminescent properties in NIR region of LaPO4:Er/LaPO4 core/shell nanoparticles

To get over the drawback of nanomaterials such as quenching by O-H group for EDWA application, LaPO4:Er/LaO4 core/shell nanoparticles were synthesized in the mixture solvent system and their properties were investigated through various spectroscopic techniques. The prepared core/shell nanoparticles have featured by the single phase of monazite structure and about 7-8 nm of particle size without agglomeration. In the NIR emission spectrum, the LaPO4/LaPO4 core/shell nanoparticles were largely increased in NIR-PL intensity due to encapsulation of the LaPO4 shell and the extension of lifetime were observed. In addition, the co-doping Yb3+ as a sensitizer of emission by Er3+ in the core/shell nanoparticles was accomplished enlargement of emission intensity at 1539 nm due to the effective energy transfer from Yb3+ to Er3+. On the other hand, the longest lifetime in the prepared core/shell nanoparticles was obtained at 1% activator concentration.