Preparation Of Ternary Sulfide Luminescent Material By Carbon-thermal Reduction Method And Their Luminescent Properties

Ba2ZnS3 and a series of single-doped,co-doped Ba2ZnS3 red phosphors have been synthesized by Carbon-thermal Reaction without using environment-hazardous raw materials and complicated process of ternary sulfides.Our aim is to develop a photoluminescence material to supply the plant,it can absorb ultraviolet light and green light and emit red light from a specific wavelength.The synthesis of Ba2ZnS3 in reactants are used(1)BaSO4,ZnSO4 and C powder;(2)BaS,ZnS and C powder;(3)BaSO4,ZnS and C of three kinds of composition.Crystallization and optical properties were investigated via powder X-ray diffraction and fluorescence spectra,respectivelPy.The results indicate that the optimal temperature of calcinations of phosphors Ba2ZnS3 is 900 OC and the optimal time of calcinations is 3.5?4.0 h.Using the first combinatorial synthesis of Ba2ZnS3 phosphors,the optimum concentration of doped Eu2+ was 1.0%;the optimum concentration of doped Mn2+was 3.5%.When Eu2+ and Mn2+ co-doped,effect of Mn2+ ion on excitation intensity greater than Eu2+.Using the second combinatorial synthesis of Ba2ZnS3 phosphors,the optimum concentration of doped Eu2+ was 2.8%;the optimum concentration of doped Mn2+ was 1.0%.When using the optimum concentration of Eu2+ or Mn2+ to explore the best concentration of co-doped,the best samples were Ba2ZnS3:2.8%Eu2+,0.25%Mn2+ and Ba2ZnS3:2.0%Eu2+,1.0%Mn2+.The first combination of reactant contains crystal water,it can be sprayed in high temperature.The second kinds of combination of reactants needs a pretreatment,the resulting of BaS is prone to hydrolysis.So the two methods all have deficiencies.So we prefer using the third method of BaSO4 and ZnS synthesis Ba2ZnS3 phosphors.The three kinds of methods to synthesize Ba2ZnS3:Eu2+,Mn2+ phosphors absorption peak near 370 nm and 550 nm,the excitation spectrum of Ba2ZnS3:Eu2+,Mn2+ phosphors has two parts,centering at 370 nm and 550 nm,respectively.Excitated by 370 nm and 550 nm,the red emission peaks peak at 630 nm and 650 nm,respectively.Using CaX2(X=F?Cl?Br.I)and other Halogen compounds additives added in sa2ZnS3:Eu2+ phosp or samples in the green region,it can enhanced absorption greatly,improve the efficiency of green light turns red greatly.Comparing the solar irradiance spectrum,absorption spectra of chlorophyll a and b,as well as PL and PLE spectra of the BZS:Eu2+,Mn2+ phosphor,the result demonstrates that Ba2ZnS3:Eu2+,Mn2+ can harvest UV and green photons of the solar spectrum and may potentially increase red light absorption of chlorophyll in agriculture crops by spectral modification,which shows that Ba2ZnS3:Eu2+,Mn2+ phosphors have potential application value in agricultural Sunlight-Conversion Film.