Colloidal Organometal Halide Perovskite (MAPbBr x I 3-x , 0≤x≤3) Quantum Dots: Controllable Synthesis and Tunable Photoluminescence.

Organic-inorganic perovskite materials, typically methylammonium lead trihalide (MAPbX3 : MA = methylammonium; X = Br, I), are recently attract enormous attention for their distinguished photo-electronic properties. The control of morphology, composition and dispersability of MAPbX3 perovskite nanocrystals is crucial for the property tailoring and still a major challenge. Here we report the synthesis of colloidal MAPbBrx I3-x (0 ≤ x ≤ 3) nanocrystals at room temperature by using alkyl carboxylate as capping ligands. These nanocrystals exhibit continuously tunable UV-vis absorption and photoluminescence (PL) across the visible spectrum, which is attributed to the quantum confinement effect with certain stoichiometry. Their unique exciton recombination dynamics was investigated and discussed.