Lu(3+)/Yb(3+) and Lu(3+)/Er(3+) co-doped antimony selenide nanomaterials: synthesis, characterization, and electrical, thermoelectrical, and optical properties

Lu(3+)/Yb(3+) and Lu(3+)/Er(3+) co-doped Sb(2)Se(3) nanomaterials were synthesized by co-reduction method in hydrothermal condition. Powder X-ray diffraction patterns indicate that the Ln(x)Ln(′)(x)Sb(2−2x)Se(3) Ln: Lu(3+)/Yb(3+) and Lu(3+)/Er(3+) crystals (x = 0.00 − 0.04) are isostructural with Sb(2)Se(3). The cell parameters were increased for compounds upon increasing the dopant content (x). Scanning electron microscopy and transmission electron microscopy images show that co-doping of Lu(3+)/Yb(3+) ions in the lattice of Sb(2)Se(3) produces nanorods, while that in Lu(3+)/Er(3+) produces nanoparticles, respectively. The electrical conductivity of co-doped Sb(2)Se(3) is higher than that of the pure Sb(2)Se(3) and increases with temperature. By increasing the concentration of Ln(3+)ions, the absorption spectrum of Sb(2)Se(3) shows red shifts and some intensity changes. In addition to the characteristic red emission peaks of Sb(2)Se(3), emission spectra of co-doped materials show other emission bands originating from f-f transitions of the Yb(3+) ions.