Closing the Yellow Gap with Eu- and Tb-Doped GaN: One Luminescent Host Resulting in Three Colours

GaN is a key material when it comes to highly efficient warm white all-nitride phosphor converted light emitting diodes (pc-LED). Here we present the doping of bulk GaN with Europium and Terbium and the combination of both resulting in intriguing luminescence properties, pushing the role of GaN:Eu,Tb as a chief component in future light emitiing diodes. By this colour tuning we prove that one luminescent host can provide three colours (red, green, orange) and even the so called "yellow gap" could be closed with a III-nitride.