Incorporation of Si-N inducing white light of SrAl2Si2O8:Eu2+,Mn2+ phosphor for white light emitting diodes

Photoluminescence (PL) and colorimetric properties of white-light emission SrAl2Si2O8:Eu2+,Mn2+ phosphor were tuned effectively through incorporating Si-N bond to the host in the form of Si3N4. A maximum solubility of Si-N bond in SrAl2-xSi2+xO8-xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2+ and an enhancement of yellow band emission peaked at ∼565 nm for Mn2+ were observed with the increase of Si-N content. These effects resulted from partial substitution of Si-N for Al1-O1 and Al4-O2 sites in SrAl2Si2O8 lattice. Eventually, a white emission with CIE chromaticity coordinates (0.287, 0.337) and color rendering index (CRI) 78.3 for SrAl2Si2O8:Eu2+,Mn2+ phosphor were achieved upon optimization to a suitable amount of Si-N.