Figure 9From: Lu3+/Yb3+ and Lu3+/Er3+ co-doped antimony selenide nanomaterials: synthesis, characterization, and electrical, thermoelectrical, and optical propertiesAbsorption spectra of co-doped antimony selenide at room temperature. (a) Lu0.04Yb0.04Sb1.92Se3 (b) Lu0.04Er0.04Sb1.92Se3.Back to article page