Great achievements in the study of LED fluorescent materials

Recently, the research team from HeFei University of Technology has made important achievements in the LED fluorescent material and the light color regulation mechanism of yttrium aluminum garnet series, which provides an important means to further improve the performance of LED fluorescent materials.

High power LED devices are widely used in home and outdoor public lighting. However, when LED lighting is used for a long time, the brightness becomes dark and the color drift will occur. Professor Chen Lei and Professor Jiang Yang of the school of material science and engineering of HeFei University of Technology have carried out scientific research on this issue. Through a series of experimental methods and theoretical calculations, a new explanation is given for the intrinsic mechanism of the spectral red shift, the decline of intensity and the deterioration of thermal stability caused by the substitution of Gd ions. Because of the larger Gd ion radius, the extrusion deformation of the electron cloud can be caused in the rigid structure of yttrium aluminum garnet, which leads to the enhancement of the crystal field, the reduction of the effective mass of electrons, the expansion of the electronic spreading level range and the decrease of the band gap, which will lead to the decrease of the luminous efficiency and the decrease of the thermal stability. Recently, the research was published in the journal Science Report of the British journal Nature.

It is introduced that this theory not only scientifically explains the luminescence of yttrium aluminum garnet after Gd substitution, but also has important guiding significance for the development of new rigid structure fluorescent materials. "In the future, we can guide the development of Artificial Gem Crystals with a specific color, giving more colorful colors, such as artificial diamonds, sapphires and ruby, which not only show high transmittance and reflective rate, but also make a special color to make it bright." Associate professor Chen Lei.

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