First-principles study of the electronic structure and optical properties of Eu2+-M (M = Mn2+, Mg2+, Li+) co-doped gamma-AlON phosphor

摘要

In our recent work we found gamma-AlON:Eu2+ phosphors to hold promise for application in white light-emitting diodes (LEDs). To obtain further insight into Eu2+-M (M = Mn2+, Mg2+, Li+) co-doped gamma-AlON, the crystal structure and the electronic and photoluminescence properties of gamma-AlON:Eu2+ M (M = Mn2+, Mg2+, Li+) phosphors were studied using first-principle calculations under the framework of density functional theory. Based on the experimental and calculated results, the structure of Eu2+-M (M = Mn2+, Mg2+, Li+) co-doped gamma-AlON was established. The calculated results demonstrate that Eu2+ and M (= Mn2+, Mg2+, Li+) can effectively improve the absorption of ultraviolet light by gamma-AlON:Eu2+. The absorption coefficient of AION:Eu2+-Li+ in the ultraviolet blue region of 275-415 nm reached 67,266 cm(-1), and the absorption coefficients of AlON:Eu2+-Mn2+ and AlON: Eu2+-Mg2+ at the same doping concentration were 51,219 and 60,575 cm(-1), respectively. Our calculations therefore show that the performance of AlON:Eu2+-Li+ is better than AlON:Eu2+-M (M = Mn2+, Mg2+).