The Synthesis And Investigation Of Spectral Properties Of Rare-Earth Ions Doped Molybdate Phosphors

Recently,white light LED?light-emitting diode?with advantages of energy conservation and environment protection,has drawn extensive attention from researchers and gradually become a predominant part in the field of lighting in the future.Presently,there are two methods with development prospect for achieving white light LED.First,blue LED chips are combined with phosphors.Second,LED chips of three primary colours are self-assembly.Phosphors play an important part in white light LED,especially for the phosphors containing molybdenum.Molybdate can effectively absorb near ultraviolet and transfer the absorbed energy to activators.Therefore,in the case of the K-M theory,the spectroscopic properties of Er³⁺ doped molybdate phosphors are investigated in this work,including:?1?For transparent medium,the method of using J-O strength parameter data to calculate the optical transition properties is more mature.But for rare earth ions doped phosphors,it is difficult to measure the ion concentration and the thickness of the samples.In this paper,the reflection spectrum of rare earth doped fluorescent powder was used to calculate pseudo J-O strength parameters,by using the proportional relationship,we get the method of real J-O intensity parameters of rare earth doped phosphors,and calculate the optical transition parameters of the powder samples by real J-O intensity parameters.?2?The power sample of NaLa?MoO₄?₂: Er³⁺ was prepared by a conventional high temperature solid method.XRD measurements was performed for the sample,and we can get the fact that,pure phase NaLa?MoO₄?₂ phosphor was achieved via high temperature solid state reaction method and Er³⁺ doping at present level does not obviously affect the crystal structure of NaLa?MoO₄?₂.The reflection spectrum of the sample was tested and the real J-O intensity parameter of NaLa?MoO₄?₂: Er³⁺ phosphor was calculated by the above method.In order to reduce the error of calculation,the center of gravity wavenumber?wavelength?was used to determine the peak position.Then the error of analysis of the calculation results of J-O strength parameters was carried out,and the true absorption cross section of the whole spectrum was obtained.?3?The power sample of KLa?MoO₄?₂: Er³⁺ was prepared by a conventional high temperature solid method.XRD measurements was performed for the sample,and we can get the fact that,pure phase KLa?MoO₄?₂: Er³⁺ phosphor was achieved via high temperature solid state reaction method.The same method was used to calculate the various parameters of the optical transition of KLa?MoO₄?₂: Er³⁺ phosphor and the feasibility of the method were verified again.