Tunable luminescence from yttrium oxide flowers using asparagine as shape modifier

Abstract

A series of Eu3+/Nd3+/Yb3+ co-doped Y2O3 flowers with different Nd3+ concentrations are synthesized using asparagine as a complexing ligand by low-temperature hydrothermal synthesis technique. The cubic crystal structure and flower like architecture morphology of the annealed co-doped Y2O3 phosphors at different synthesis temperatures have been confirmed from XRD and FESEM analysis. The photoluminescence study of the developed phosphors has been performed by using excitations at 220 nm, 808 nm and 980 nm, and the responsible mechanisms have been discussed in detail. Dipole-dipole interaction is found responsible for concentration quenching with inter-ionic separation ∼15.27 Å among the Nd3+ ions. Asymmetric ratio is calculated to be 3.01 with respective to Eu3+ ions in co-doped Y2O3 host lattice. The spectral characteristics have been described via nephelauxetic ratio and Judd–Ofelt parameters in co-doped Y2O3 under UV excitation. Two photon process dominates the upconversion luminescence on 808 nm irradiation. CIE color coordinates clearly indicates that co-doped Y2O3 phosphors can be further used for multi-color labeling applications. Moreover, because of the intrinsic magnetic moment of Nd3+ ions, the developed Eu3+/Nd3+/Yb3+ co-doped Y2O3 phosphors exhibit paramagnetic behavior with magnetization value 0.0064 emu/g at 300 K.