The geometrical structure and electronic properties of trivalent Ho3+ doped Y2O3 crystals: a first-principles study. Issue 48 (4th August 2020) - Ju, Meng
Abstract : Our study successfully identified the ground-state structure of Ho 3+ -doped Y2 O3 crystal for the first time. Abstract : Trivalent rare-earth holmium ion (Ho 3+ ) doped yttrium oxide (Y2 O3 ) has attracted great research interest owing to its unique optoelectronic properties and excellent performances in many new-type laser devices. But the crystal structures of the Ho 3+ -doped Y2 O3 system (Y2 O3 : Ho) are still unclear. Here, we have carried out a first-principle study on the structural evolution of the trivalent Ho 3+ doped Y2 O3 by using the CALYPSO structure search method. The results indicate that the lowest-energy structure of Ho 3+ -doped Y2 O3 possesses a standardized monoclinic P 2 phase. It is found that the doped Ho 3+ ion are likely to occupy the sites of Y 3+ in the host crystal lattice, forming the [HoO6 ] 9− local structure with C 2 site symmetry. Electronic structure calculations reveal that the band gap value of Ho 3+ -doped Y2 O3 is approximately 4.27 eV, suggesting the insulating character of Y2 O3 : Ho system. These findings could provide fundamental insights to understand the atomic interactions in crystals as well as the information of electronic properties for other rare-earth-doped materials.