Near-White Light and Near-Infrared Luminescence in Perovskite Ga:LaCrO 3

We report the realization of near-white light emission (near-WLE) and the selective tuning to the near-infrared (NIR) luminescence from Ga substituted lanthanum chromite perovskite with electron-beam excitation. The Ga3+ acts as an electron donor in the LaCrO3 system and the emission intensity increases with Ga substitution. The near-WLE in CL, arises from the combination of 4T1(F)→4A2 (blue), 4T1(P)→4A2 (green) and 4T2→4A2 (red) spin allowed transitions and 2E→4A2 spin forbidden transitions from the Cr3+ ion. The spin allowed transitions from the Cr3+ ions are not common, however can be accomplished by adjusting the Cr3+/Ga3+ ion concentration in the host lattice. The NIR emission originates from the selective 2E→4A2 transition, which dominates with the increasing concentration of Ga3+ ions. The Density Functional Theory (DFT) calculations point out the presence of extra electronic states with Ga substitution, which validates the observation of NIR emission in Ga substituted samples.