Deciphering the structures and electronic features of Yb3+-doped Y2O3 crystal: A theoretical perspective study

Abstract

Considerable research interests have been paid to the rare-earth (RE) Yb3+-doped Y2O3 crystal which is of great potential for application as a solid-state laser because of its remarkable optoelectronic and physical properties. However, the detailed information of its microstructure is still lacking. Here, we have performed a systematically study of the structural evolution and electronic features of Yb3+-doped Y2O3 crystal by using the CALYPSO method and first-principle calculations. A novel stable phase of Yb3+-doped Y2O3 with R-3 space group has been uncovered for the first time. The obtained crystal structure indicates that the impurity Yb3+ ions are likely to substitute the Y3+ ions, forming a cage-like structure. Our simulated X-ray diffraction patterns of the lowest-energy structure show excellent agreement with the observed data, which demonstrates the accuracy of the present calculation. By analyzing the electronic band structures, we found the elimination of the insulated characters of Yb3+-doped Y2O3, resulting in an energy gap of 1.64 eV. The electron localization function and Bader charge analysis of Yb3+-doped Y2O3 are calculated and the results suggest that the Y-O bonds in Y2O3:Yb are ionic. These results can offer significant information of RE doped laser materials and serve as guides for the further investigation of such materials.