A theoretical study of the effect of Eu ion dopant on the electronic excitations of yttrium oxide and yttrium oxy-sulphide

Recently, lanthanide ion doped yttrium oxide (Y₂O ₃)compounds have been attracting attention in applications concerning opto-electronic materials such as laser devices and field-emission displays. Consequently, study on the excited state of lanthanide ion doped Y ₂O₃ is of major significance. In the present work, we report studies performed on the electronic excited states of undoped and Eu ³⁺ doped Y₂O₃ as well as yttrium oxy-sulphide (Y₂O₂S) clusters using the time dependent density functional theory method to unveil the influence of europium ion in yttrium oxide compounds. The ground state electronic properties of undoped and europium ion doped clusters at different spin multiplicities were obtained using the density functional theory method. The calculated results were compared with the available experimental results. The calculated absorption spectrum of Eu doped Y₂O₃ cluster shows quantitative agreement with experimental spectra. The absorption spectra of europium ion doped Y ₂O₃ and Y₂O₂S clusters have shown additional bands in the higher wavelength region due to the transitions between f-orbitals in the europium ion.