Defects & Luminescence of Lu3Al5O12 Phosphor Doped with Na Ion

A systematic first-principles study on occupation of Na ions in Lu3Al5O12 (LuAG) lattice and effect on oxygen vacancies, dominant intrinsic antisite defect (AD) was performed. We found that the Na prefer to be occupied at Lutetium sites. The energy of defect complex of Na and oxygen vacancies is lower than that of isolated oxygen vacancies. The band structure calculation illustrates that Na will eliminate the impurity states introduced by oxygen vacancies in the band gap and it also will inhibit the AD. We measured X-ray excited luminescence spectra, the variation of luminescence intensity verified our calculation results.