Chemical trends of Mn~(4+) emission in solids

摘要

Mn~(4+) is known to activate red emission in many materials. However, the existing Mn~(4+) activated red phosphors have relatively long emission wavelengths and are therefore inefficient for general lighting purposes. Density functional calculations are performed on a large number of Mn~(4+) doped materials with diverse crystal structures to understand how material properties of different hosts affect the emission energy of the Mn~(4+) dopant. The results show that weak Mn~(4+)-ligand hybridization generally leads to higher Mn~(4+) emission energies. Host materials allowing long Mn-ligand distance and/or significant distortion of bond angles around the Mn octahedral site are shown to have higher emission energies. Several new oxide host materials are found for Mn~(4+). Their emission energies are found to be higher than those currently known for Mn~(4+) doped oxides and should be closer to that of Y2O3:Eu~(3+), which is the current commercial red phosphor for fluorescent lighting.