Disordered langasites LaGaMO : Eu (M = Si, Ge, Ti) as red-emitting LED phosphors.

Polycrystalline powders of La3Ga5SiO14 (LGSi), La3Ga5GeO14 (LGGe), and La3Ga5TiO14 (LGTi) doped with Eu3+ were studied with respect to their use as luminescent materials in solid state lighting based on light-emitting diodes. The langasites were synthesized with up to 35% of trivalent europium to achieve the highest possible doping amount. According to diffuse reflection measurements the undoped compounds have band gap energies of 4.