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

다국어 초록 (Multilingual Abstract)

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