Study Of Photoluminescence Properties Of Er³⁺/Yb³⁺ Co-doped Gadolinium Molybdate Nanocrystals

Up-conversion fluorescence properties of nano-materials with rare earth dopedhave been widely studied. This kind of materials have been applied in a series of fields.But the luminous intensity is expected to be increased. The choice of matrix isimportant to the luminous intensity. The phonon energy of matrix should be low, andthe matrix should have good chemical stability. The tungstate and molybdate materialbecome the research hotspot because of the better matrix conditions in recent years.Gadolinium molybdate （Gd₂（MoO₄）₃） is researched as the matrix of nano-materials withrare earth doped in this paper. The upconversion fluorescence properties of Er³⁺andEr³⁺/Yb³⁺doped Gd₂（MoO₄）₃was studied. various factors that influence the temperaturemeasurement sensitivity was studied at last.Er³⁺doped Gd₂（MoO₄）₃phosphors with different concentrations were prepared bya sol-gel method. The field emission scanning electron microscopy （FE-SEM） images,EDS and X-ray diffraction（XRD）patterns were investigated. The fluorescence spectrumof the samples were measured. The crytal phase of different samples are all Monoclinic.The fluorescence intensity is strongest when the concentration of Er³⁺ion was20%.This shows Gd₂（MoO₄）₃is a good up conversion （UC） matrix with high quenchingconcentration. The fluorescence spectrum was measured under the different excitationpower. The phenomenon of the intense green but weak red UC luminescence wasexplained by analyzing the UC mechanism of fluorescence.Er³⁺/Yb³⁺co-doped Gd₂（MoO₄）₃phosphors with different Yb³⁺concentrationswere prepared by a sol-gel method. The up-conversion fluorescence spectrum of thesamples were measured by the iHR550spectrograph under the980nm excitation. Thedouble logarithm curve of the excitation power and the fluorescence intensity wasploted. The conversion mechanism of fluorescence was analyzed. The phenomenon ofthe intense green but weak red UC luminescence was explained by analyzing the UCmechanism of fluorescence. Under the nanosecond pulse excited, the fluorescencelifetime of samples was measured.Temperature measurement has been achieved by the fluorescence intensity ratio （FIR）.The two fluorescent peaks,530nm and550nm, are emissioned from the two thermalcoupling level²H_11/2and⁴S_3/2to⁴I（15/2）. The sensitivity curve was matched and thehigher value was got from550K to650K. In consideration of the temperature effect ofpump laser, the impact of different facts was studied.