Impact of Annealing Temperature on Lanthanum Erbium Telluride (La0.1Er0.2Te0.2) Nanoparticles Synthesized via Hydrothermal Approach

In this study, we synthesized La0.1Er0.2Te0.2 nanoparticle using 0.2 mol of Er(NO3)3·5H2O, 0.1 mol of La(NO3)3·6H2O, and 0.2 mol of Te(NO3)4 through hydrothermal and doctor blade methods. The La0.1Er0.2Te0.2 material reveals a hexagonal structure corresponding to a 2theta angle of 13.263°. 15.375°. 16.943°. 18.924°. 25.788°. and 27.356° for La0.1Er0.2Te0.2 unannealed and 13.302°, 15.489°, 16.960°, 19.055°, 25.862°, and 27.373° for annealed samples. The XRD pattern showed that the crystallinity increased with higher annealing temperature. Unannealed La0.1Er0.2Te0.2 had glow-like nanoparticles. The La0.1Er0.2Te0.2 nanoparticles showed high absorbance in the visible area of the spectra with 0.648 a.u. The absorbance of the material decreased as the annealing temperature increased. The higher the annealing temperature, the lower the absorbance of the material. The unannealed nanoparticle has a bandgap energy of 3.50 eV. The annealing nanoparticles have a bandgap of 3.27 to 2.26 eV. The higher the annealing temperature, the lower the bandgap of the material.