Eu2+ luminescence in MAl3BO7 aluminoborates (M=Ca, Sr, Ba)

Abstract Three new aluminoborates having the composition MAl 3 BO 7 , where M = Ca,Sr or Ba, have been prepared. X-ray diffraction data indicate that all the phases are monoclinic, with close structural similarity to the meta stable aluminate, SrAl 4 O 7 . These aluminoborates are good host lattices for Eu 2+ luminescence. The emission spectra show multiple bands in the blue region, corresponding to two inequivalent sites in each case, with one of them having quantum efficiency ≳ 75%. In the case of SrAl 3 BO 7 :Eu 2+ , the d–f band emission dominates at 300 K whereas at 77 K both d–f band and f–f line emissions are observed. Efficient Eu 2+ →Mn 2+ energy transfer is observed in MAl 3 BO 7 leading to strong green emission of Mn 2+ in the tetrahedral sites.