Enhancement of photosynthetic action spectrum for 660 nm-featured phase-pure (Ba,Sr)_3MgSi_2O_8: Eu~(2+), Mn~(2+) phosphor by spray-combustion synthesis

摘要

Dual band emissions positioned at both 660 and 430 nm of (Ba, Sr)_3MgSi_2O_8: Eu~(2+), Mn~(2+) phosphor was achieved via spray-combustion synthesis procedure. At a specific limited solid solubility composition Ba_(1.3)Sr_(1.7) MgSi_2O_8, the secondary green-emitting phases of (Ba, Sr)_2SiO_4 or (Ba, Sr)MgSiO_4 were effectively suppressed to give out the desired 660 nm broad emission. An enhancement of photoluminescence (PL) intensity for 660 nm red emission originated from Mn transition was observed in combustion synthesis samples, indicating an intrinsic promotion of energy transfer from Eu~(2+) to Mn~(2+) in (Ba, Sr)_3MgSi_2O_8 host. This PL enhancement to 660 nm emission is probably ascribed to an effective reduction of Mn ion in the combustion process with the aid of decomposed reductive radicals formed in situ upon fuel ignition. The crystallized particle size varies in the range from 5 to 20 μm depending on process parameters. A near ultraviolet LED illumination prototype packaged with as-prepared phosphor exhibits to be violet in color. This combustion synthesis process provides an effective means for PL enhancement of phase-pure (Ba,Sr)_3MgSi_2C)_8: Eu~(2+), Mn~(2+) phosphors to construct the photosynthetic action spectrum.