Observation of exceptional strong emission transitions 5Dj (j=1−3) to 7Fj (j=1−3): Multicolor from single Eu3+ ion doped La2O3 nanoparticles

► As prepared samples shows biphasic nature. ► La2O3 is sensitive to ambient environment. ► Exceptional strong emission transitions of 5Dj (j=1−3) to 7Fj (j=1-3). ► Multicolor tuning from singly doped La2O3.