Synthesis of novel LnxSb2−xSe3 (Ln: Lu3+, Ho3+, Nd3+) nanomaterials via co-reduction method and investigation of their physical properties

Rare earth ion (Lu3+, Ho3+, Nd3+)-doped Sb2Se3 nanomaterials are synthesized by a co-reduction method in hydrothermal condition. Powder XRD patterns indicate that the LnxSb2−xSe3 crystals (Ln = Lu3+, x = 0.00–0.12; Ho3+, x = 0.00–0.1 and Nd3+, x = 0.00–0.09) are isostructural with Sb2Se3. SEM images show that doping of Ho3+ ions in the lattice of Sb2Se3 results in nanorods while that in Nd3+and Lu3+leads to nanoflowers and nanoparticles, respectively. High-resolution transmission electron microscopic (HRTEM) studies reveal that the Sb2Se3 and Sb1.90 Ho0.1Se3are oriented in the [1 0 −1] growth direction. UV–vis spectra show that an increasing concentration of Ln3+ions increases the intensity of some peaks in the absorption spectrum of Sb2Se3 related to electronic transitions of the Ln3+ ions in case of Ho3+ and Nd3+ doped nanomaterials. Emission spectra of doped materials, in addition to the characteristic red emission peaks of Sb2Se3, show other emission bands originating from f–f transitions of the Ho3+ ions. The electrical conductance of Ln-doped Sb2Se3 is higher than the undoped Sb2Se3, and increases with temperature.