The field of luminescent materials has been and will stay important for science and society with countless applications in healthcare, security, information- and display technology, lighting and many more. Luminescent materials are without a doubt a key enabling technology in optics and photonics. Its current growth is driven by industrial needs for new or improved phosphors for white and IR LEDs, new types of displays with better color purity, new afterglow phosphors for small animal imaging, or denser scintillators for security and medical imaging applications with improved sensitivity and spatial resolution. Developments are also driven by new synthesis approaches enabling for example highly efficient core multi-shell quantum dots. New fundamental insights in the absolute energy of ground- and excited states of rare earth and transition metal ions have made deliberate design of new materials possible, and provide better control of charge- and energy transfer processes between ions.