Emission characteristics of white light phosphor

White light LED was successfully fabricated by converting near-UV LED emission (390-420 nm) with a new white light phosphor. This new white phosphor was consisted of three fluorescence materials; two strontium aluminates based with lanthanide oxides, SrAl/sub 2/O/sub 4/:Eu/sup 2+/ (for green (520 nm) emission) and Sr/sub 4/Al/sub 14/O/sub 25/:Eu/sup 2+/ (for blue (490 nm) emission) and new organometallic Eu complex, (for red (614 nm) emission). These materials have good absorption in the 300-500 nm range and have high quantum efficiencies (4.7-24.5%). The white light LED has a CIE value of (0.321, 0.365, 0.314).

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White LED is an emerging solid light source that potentially can replace the traditional light source.[1] The common way to make a white LED is by using phosphor to convert the UV LED emission into broadband white-light emission. [2]–[5] In this article, we used RBG phosphors and near-UV LED to fabricate white LED. Three materials were used as light converters, and a new Eu organometallic complex. Several optical measurements were taken before making use of the materials, such as photoluminescence excitation (PLE), emission spectra (PL), quantum efficiency and decay lifetime. Based on the optical measurement results, those three materials have good absorption in Near-UV range and also a good emission in visible. Thus, a novel mix of inorganic/organic luminescence materials produced a new white light phosphor. The white phosphor was applied onto the near-UV LED. As a result, a white emission LED is fabricated. Preliminary lifetime test indicated that the phosphor is robust showing no degradation over. a period of 100 hrs. This offers potential application in solid state white light source.