Enhanced luminescence properties of monodisperse trioctylphosphine oxide-capped Nd3+-doped LaF3 nanorods without OH groups

Nd3+-doped LaF3 nanorods without –OH groups were synthesized via a simple thermolysis method in trioctylphosphine oxide (TOPO) solvent. FTIR spectrum indicates that TOPO molecules have been coordinated to LaF3:Nd nanorods surface, which reduce the number of –OH groups on the nanoparticles surface effectively. The structure and morphology of as-synthesized nanorods were characterized. The possible grow mechanism of LaF3:Nd nanorods has been also discussed in detail. The TOPO capped LaF3:Nd nanoparticles preferentially grow along the <0 0 0 1> orientation under high temperature. Based on the absorption spectra and Judd–Ofelt theory, higher value of emission cross-section for 4F3/2→4I11/2 transition of Nd3+ was calculated to be 3.22 × 10−20 cm2. The strong fluorescence intensity of LaF3:Nd nanorods in chloroform demonstrates that these nanorods are promising luminescence materials.