Highly Emissive Divalent-Ion-Doped Colloidal CsPb(1-x)M(x)Br(3) Perovskite Nanocrystals through Cation Exchange.
Highly Emissive Divalent-Ion-Doped Colloidal CsPb(1-x)M(x)Br(3) Perovskite Nanocrystals through Cation Exchange.
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DOI：
10.1021/jacs.6b13079
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发表时间：
2017-03-22
影响因子：
15
通讯作者：
de Mello Donega C
中科院分区：
文献类型：
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作者：
van der Stam W;Geuchies JJ;Altantzis T;van den Bos KH;Meeldijk JD;Van Aert S;Bals S;Vanmaekelbergh D;de Mello Donega C
胶体CsPbX 3（X = Br，Cl，I）钙钛矿纳米晶由于其优异的光电性能而成为有前途的荧光粉和太阳能电池材料。这些性能不仅可以通过控制NC的大小和形状来定制，还可以通过拓扑异构阴离子交换来调整合成后的组成。相比之下，通过阳离子交换的性质控制对于胶体CsPbX 3 NCs仍然不发达。在这里，我们提出了一种方法，允许在胶体CsPbBr 3 NC的部分阳离子交换，其中Pb 2+被交换为几个等价的阳离子，导致掺杂的CsPb 1-xMxBr 3 NC（M= Sn 2+，Cd 2+，和Zn 2 +; 0 < x ≤ 0.1），与原始NC形状的保留。母体NC的尺寸也保留在产物NC中，除了在掺入客体阳离子后晶胞的小（几%）收缩之外。部分Pb 2+交换M2+导致光谱蓝移，同时保持母体CsPbBr 3 NC的高光致发光量子产率（>50%）、尖锐吸收特征和窄发射。在光谱中的蓝移归因于晶格收缩，伴随着Pb 2+的M2+阳离子交换，并观察到与晶格收缩成线性比例。这项工作为设计卤化物钙钛矿NC的性能开辟了新的可能性，迄今为止，这被证明是唯一已知的系统，其中阳离子和阴离子交换反应可以顺序组合，同时保持原始NC形状，从而产生组成多样的钙钛矿NC。
Colloidal CsPbX3 (X = Br, Cl, and I) perovskite nanocrystals (NCs) have emerged as promising phosphors and solar cell materials due to their remarkable optoelectronic properties. These properties can be tailored by not only controlling the size and shape of the NCs but also postsynthetic composition tuning through topotactic anion exchange. In contrast, property control by cation exchange is still underdeveloped for colloidal CsPbX3 NCs. Here, we present a method that allows partial cation exchange in colloidal CsPbBr3 NCs, whereby Pb2+ is exchanged for several isovalent cations, resulting in doped CsPb1–xMxBr3 NCs (M= Sn2+, Cd2+, and Zn2+; 0 < x ≤ 0.1), with preservation of the original NC shape. The size of the parent NCs is also preserved in the product NCs, apart from a small (few %) contraction of the unit cells upon incorporation of the guest cations. The partial Pb2+ for M2+ exchange leads to a blue-shift of the optical spectra, while maintaining the high photoluminescence quantum yields (>50%), sharp absorption features, and narrow emission of the parent CsPbBr3 NCs. The blue-shift in the optical spectra is attributed to the lattice contraction that accompanies the Pb2+ for M2+ cation exchange and is observed to scale linearly with the lattice contraction. This work opens up new possibilities to engineer the properties of halide perovskite NCs, which to date are demonstrated to be the only known system where cation and anion exchange reactions can be sequentially combined while preserving the original NC shape, resulting in compositionally diverse perovskite NCs.