In this paper we give a summary of technologies that are essential for phosphor developing: Characterization of the pure phosphor powders with methods like powder X-ray diffraction (XRD), optical spectroscopy, scanning electron microscopy (SEM), etc. give strong hints for and how to improve the phosphor's performance. The final proof of the phosphor's quality is obtained by application testing in the LED. Latter is a very useful tool for materials researchers and developers to adopt the phosphor to the LED device. Last but not least we demonstrate advantages of a phosphor fabrication process by using wet chemical routes in comparison to the traditional and widely applied solid state diffusion methods ("mix & fire").