Influence of Eu-substitution on luminescent CH₃NH₃PbBr₃ quantum dots

We report a series of Eu-substituted methylammonium lead tribromide quantum dots (MAPb1-xEuxBr3 QDs). The crystallinity of these QDs increases with increasing Eu content, while there is only a small change in the lattice constant, and the morphology of the MAPb1-xEuxBr3 QDs is unaffected by the Eu content. This demonstrates that Eu is a suitable element for substituting Pb while retaining the original crystal structure. We observe blue photoluminescence (PL) consistent with Eu2+, which, at high Eu content (x = 0.3), contributes luminescence intensity equal to the green PL of unsubstituted MAPbBr3 QDs. As Eu is a less toxic substitute for Pb, that also provides blue luminescence, MAPb1-xEuxBr3 QDs may prove to be a valuable optoelectronic material.