Unveiling the Excited-State Dynamics of Mn2+in 0D Cs4PbCl6Perovskite Nanocrystals

Doping is an effective strategy for tailoring the optical properties of 0D Cs4PbX6(X = Cl, Br, and I) perovskite nanocrystals (NCs) and expanding their applications. Herein, a unique approach is reported for the controlled synthesis of pure-phase Mn2+-doped Cs(4)PbCl(6)perovskite NCs and the excited-state dynamics of Mn(2+)is unveiled through temperature-dependent steady-state and transient photoluminescence (PL) spectroscopy. Because of the spatially confined 0D structure of Cs(4)PbCl(6)perovskite, the NCs exhibit drastically different PL properties of Mn(2+)in comparison with their 3D CsPbCl(3)analogues, including significantly improved PL quantum yield in solid form (25.8%), unusually long PL lifetime (26.2 ms), large exciton binding energy, strong electron-phonon coupling strength, and an anomalous temperature evolution of Mn2+-PL decay from a dominant slow decay (in tens of ms scale) at 300 K to a fast decay (in 1 ms scale) at 10 K. These findings provide fundamental insights into the excited-state dynamics of Mn(2+)in 0D Cs4PbCl6NCs, thus laying a foundation for future design of 0D perovskite NCs through metal ion doping toward versatile applications.