Dajian Wang

Investigation of Eu–Mn energy transfer in A3MgSi2O8:Eu2+, Mn2+ (A=Ca,Sr,Ba) for light-emitting diodes for plant cultivation

We report a plant growth lamp utilizing near-ultraviolet light-emitting diode and A3MgSi2O8:Eu2+, Mn2+ (A=Ca,Sr,Ba) phosphors with emission spectra consisting of blue and red bands, which conform well to the action spectra of plants and absorption spectra of chlorophylls. Either peak positions of the two bands or intensity ratio of red to blue band can be tailored by tuning the compositions of the cations. Eu–Mn energy transfer in the phosphors was investigated on the bases of photoluminescence, life decay time, and microstructure. This functional solid-state lighting provides a simple, compact, and efficient solution to illuminator for plant cultivation.

The Origin of 505 nm-Peaked Photoluminescence from Ba3MgSi2O8:Eu2+, Mn2+ Phosphor for White-Light-Emitting Diodes

A 505 nm-peaked photoluminescence of Ba 3 MgSi 2 O 8 :Eu 2+ , Mn 2+ phosphor for white-light-emitting diodes originating from an intermediate phase, Ba 2 SiO 4 :Eu 2+ , is found. The corresponding optical properties of this 505 nm-peaked photoluminescence resemble those of Ba 2 SiO 4 :Eu 2+ well. X-ray diffraction (XRD) results confirm the existence of Ba 2 SiO 4 in the Ba 3 MgSi 2 O 8 . The formation of Ba 2 SiO 4 is ascribed to the phase equilibrium during firing. Addition of flux inhibits the formation of intermediate phases and improves the crystallinity of Ba 3 MgSi 2 O 8 . Specifically, as a proper amount of NH 4 Cl is added, the 505 nm-peaked photoluminescence disappears and the XRD peaks attributed to Ba 2 SiO 4 disappear as well.