Bhaumik Saikat, Veldhuis Sjoerd A, Muduli Subas Kumar, Li Mingjie, Begum Raihana, Sum Tze Chien, Mhaisalkar Subodh, Mathews Nripan
Energy Research Institute@NTU (ERI@N), Nanyang Technological University, Research Techno Plaza, X-Frontier Block, Singapore, 637553, Singapore.
School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore, 637371, Singapore.
Chempluschem. 2018 Jun;83(6):514-520. doi: 10.1002/cplu.201800135.
A new two-step synthetic protocol to yield monodisperse spherical zero-dimensional (0D) Cs PbX nanocrystals (NCs) and three-dimensional (3D) CsPbX NCs is described. The first step of the reaction involves the colloidal synthesis of spherical PbX seed NCs, which are subsequently converted to Cs PbX and CsPbX NCs through hot injection of a Cs precursor at the desired reaction temperatures. By employing less reactive Pb and halide precursors, the reaction time was extended from several seconds to about five minutes, thereby allowing greater control during the crystallization and growth stages. The adjustment of halide ratios allows color tuning over a wide spectral range (411-669 nm) for CsPbX NCs, with high photoluminescence quantum yields (6-65 %) and narrow emission line widths (ca. 13-30 nm). We envisage our spherical NCs to become a starting point for shell growth (e.g., ZnS, CdS, PbS) by overcoming the difficulty of shell growth around thermodynamically unfavorable (i.e., high surface free energy) cuboid-shaped NCs.
本文描述了一种新的两步合成方法，用于制备单分散球形零维（0D）CsPbX纳米晶体（NCs）和三维（3D）CsPbX NCs。反应的第一步涉及球形PbX种子NCs的胶体合成，随后通过在所需反应温度下热注入Cs前驱体将其转化为CsPbX和CsPbX NCs。通过使用反应活性较低的Pb和卤化物前驱体，反应时间从几秒延长至约五分钟，从而在结晶和生长阶段实现了更好的控制。通过调整卤化物比例，CsPbX NCs可在较宽光谱范围（411 - 669 nm）内实现颜色调节，具有高光致发光量子产率（6 - 65%）和窄发射线宽（约13 - 30 nm）。我们设想，通过克服围绕热力学不利（即高表面自由能）的长方体形NCs进行壳层生长的困难，我们的球形NCs将成为壳层生长（如ZnS、CdS、PbS）的起点。
