Study On Preparation And Luminescence Properties Of CaMoO₄:Eu Red Emitting Micronphosphor For White LEDs

White LED will become the mainstream of the future lighting industry development because of its energy conservation and environmental protection, and many other advantages. Using near-UV chip + trichromatic phosphor converted for white light illumination is considered to be a promising way in the realization of white LED phosphor. Compared with the mature green and blue fluorescent powder, there is an urgent need to red emitting phosphor materials can be effectively excited by near ultraviolet light. In this paper, the Eu3+ doped various types of tungstate materials as red emitting phosphors were prepared and studied.CaMoO4 micrometer phosphors doped with Eu3+ of different concentrations were prepared by chemical precipitation method. The photoluminescence properties of the samples were studied in detail. The results indicate that CaMoO4: Eu can be effectively excited by blue light and near UV light, and emit red light with high purity. The order of magnitude of factor is 10-2, so the electron-phonon coupling action is weak in the sample. The transition intensity parameter ?2 of Eu3+ increases with the increase of doping concentration. But the quantum efficiency deceases with the increase of doping concentration. The best doping concentration of Eu3+ is 25% was obtained by drawing concentration quenching curve. The energy transfer of Eu3+ in CaMoO4 host is exchange interaction. The CaMoO4: Eu micrometer phosphors is a red phosphor material with excellent property.The main innovation points are as follows.1. The sample were prepared by chemical precipitation method in this paper. Comparing with other preparation methods, this method is easy operation and. And the sample rules of the morphology and uniform distribution.2. Among the RE ions, the trivalent europium ion, Eu3+, is usually adopted as a red emitting center. Especially, Eu3+ doped tungstates possess strong absorption corresponding to Eu3+ 4f –4f transition in near UV and blue light region. There could be a new type of near-UV(or blue) excited white light-emitting diode(LED) with a red phosphor3. The energy transfer and electron–phonon coupling characteristics of Eu3+ doped CaMoO4 optical materials were studied detailedly in this paper. The energy transfer type causing Eu3+ concentration quenching between Eu3+ ions was notarized, and the critical energy transfer distance was calculated. In addition, the Huang-Rhys fators of samples were calculated through the phonon sideband spectra that we get, and was discussed briefly.