Co-precipitation synthesis and upconversion luminescence properties of ZrO2:Yb3+-Ho3+

ZrO2:Yb3+-Ho3+ phosphors with different Yb3+ doping concentration have been prepared by co-precipitation method. X-ray diffraction (XRD), scanning electron microscope (SEM) and photoluminescence spectra were used to characterize the properties of ZrO2:Yb3+-Ho3+ phosphors. Different phases of ZrO2 can be obtained by changing the concentration of Yb3+. Under the 980 nm excitation, the sample gives a set of light: strong green (539 nm), weak red (670 nm) and near-infrared (760 nm). The upconversion luminescence is based on two-photon absorption by the energy transfer from the donor (Yb3+) to the acceptor (Ho3+). All the results indicate that ZrO2:Yb3+-Ho3+ phosphors could be a promising biological labelling material.