Preparation and upconversion property of TeO2:Er3+/Yb3+ nanoparticles

► Different crystal structure of TeO2 nanoparticles were used as the host materials to prepare TeO2:Er3+/Yb3+ nanoparticles. ► Upconversion luminescence of TeO2:Er3+/Yb3+ nanoparticles was investigated. ► The emission intensities of α (or β)-TeO2:Er3+/Yb3+ nanoparticles were stronger than those of (α + β)-TeO2:Er3+/Yb3+ nanoparticles.