Eu(II) luminescence in the perovskite host lattices KMgH3, NaMgH3 and mixed crystals LiBaxSr1−xH3
Bright luminescence of Eu(II) doped into the cubic perovskites KMgH3 and mixed crystal compounds LiBaxSr1−xH3 was observed and assigned to the 4f65d–4f7 emission of Eu2+. KMgH3:Eu2+ shows an extremely bright yellow emission, whereas the wavelength of the emission maximum in LiBaxSr1−xH3:Eu2+ depends on the value of x and ranges from yellow to green. Furthermore, an extremely wide red shift in the emission energy is observed for the orthorhombically distorted perovskite NaMgH3:Eu2+. Additionally, we review the crystal structure of KMgH3 using density functional calculations.