Pure Cs4PbBr6: Highly Luminescent Zero Dimensional Perovskite Solids
Pure Cs4PbBr6: Highly Luminescent Zero Dimensional Perovskite Solids
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DOI：
10.1021/acsenergylett.6b00396
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发表时间：
2016-10-01
影响因子：
22
通讯作者：
Bakr, Osman M.
中科院分区：
文献类型：
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作者：
Saidaminov, Makhsud I.;Almutlaq, Jawaher;Bakr, Osman M.
所谓的零维钙钛矿，如Cs4 PbBr 6，承诺出色的发射性能。然而，Cs4 PbBr 6主要通过熔融前体制备，这通常导致不期望的相的共形成。在这里，我们报告了一个简单的低温溶液处理合成纯Cs4 PbBr 6具有显着的发光性能。我们发现，纯Cs4 PbBr 6在固体形式表现出45%的光致发光量子产率（PLQY），相比之下，它的三维对应物，CsPbBr 3，表现出超过2个数量级低PLQY。Cs4 PbBr 6的这种PLQY显著高于其他固体形式的低维金属卤化物钙钛矿衍生物和钙钛矿纳米晶体的PLQY。我们将PL的这种急剧增加归因于高激子结合能，我们估计其为-353 meV，这可能是由Cs4 PbBr 6的独特Bergerhoff-Schmitz-Dumont型晶体结构引起的，其中金属卤化物包含的八面体在空间上受到限制。我们的发现将这类钙钛矿衍生物带到了颜色转换和发光应用的最前沿。
So-called zero-dimensional perovskites, such as Cs4PbBr6, promise outstanding emissive properties. However, Cs4PbBr6 is mostly prepared by melting of precursors that usually leads to a coformation of undesired phases. Here, we report a simple low-temperature solution-processed synthesis of pure Cs4PbBr6 with remarkable emission properties. We found that pure Cs4PbBr6 in solid form exhibits a 45% photoluminescence quantum yield (PLQY), in contrast to its three-dimensional counterpart, CsPbBr3, which exhibits more than 2 orders of magnitude lower PLQY. Such a PLQY of Cs4PbBr6 is significantly higher than that of other solid forms of lower-dimensional metal halide perovskite derivatives and perovskite nanocrystals. We attribute this dramatic increase in PL to the high exciton binding energy, which we estimate to be-353 meV, likely induced by the unique Bergerhoff-Schmitz-Dumont-type crystal structure of Cs4PbBr6, in which metal-halide-comprised octahedra are spatially confined. Our findings bring this class of perovskite derivatives to the forefront of color-converting and light-emitting applications.