Sol–gel matrix for YAG:Ce phosphors in pc-LEDs

Sol–gel formulations were applied to replace silicone as matrix material for phosphors in pc-LEDs. The content of organic groups was minimized in order to reduce yellowing during the operation of the elements. It was possible to evenly embed YAG:Ce particles in sol–gel binders. Further processing on LED chips resulted in operational light sources; and their performance was compared to standard silicone-based elements. Additional deposition of ALD laminates seals possible defects within the sol–gel matrix as additional protection of the phosphors and the underlying LEDs. In lighting technology, the emission of LEDs is converted into the visible range by fluorescent particles embedded in silicone. The thermal stability of silicone limits the operating temperature and thus the light intensity. By using innovative temperature-stable sol–gel matrix materials, commercial LED chips can be operated at higher currents and thus their emission is significantly increased.