What is tungsten-molybdate system?

Tungsten-molybdenum colloid is the structure of scheelite. As the matrix of red phosphor, the doped luminescent ions have two sharp excitation absorption peaks near the ultraviolet (~ 395nm) and blue (~ 465nm). This is very consistent with the current commercial LED chip output wavelength, In addition, the synthesis temperature of tungsten-molybdate phosphors is generally low. The phosphors of red phosphor system used in white tungsten-molybdate LED have become one of the most concerned fluorescent materials in the research field of red phosphors. A series of tungsten-molybdate red phosphors were synthesized by solid state reaction at high temperature, sol-gel method, combustion removal and hydrothermal synthesis methods and so on.

Excitation,which is unfavorable to the wavelength fluctuation of real chips, so researchers try to widen the excitation band of tungsten-molybdate substrate phosphors by adding. The red phosphors were prepared by high temperature solid state method. The results show that the excitation intensity of the phosphors at 465nm can be improved, and the phosphors prepared can meet the emission wavelength requirements of blue LED chips. In order to widen the excitation spectrum of tungsten-molybdate red phosphors in the near ultraviolet wavelength region, the phosphors with Bi+ were synthesized. The UV excitation band of phosphors is affected by two factors: charge transfer state and 6s migration to 6p. This effect results in the red shift of the excitation spectrum of the phosphor and the enhancement of the peak value of the red emission in the emission spectrum.

It is also possible for the excited spectrum to produce a broadband absorption peak in the tungsten molybdate complex with multiple elements double perovskite structure.

This article is from Allicdata Electronics Limited.