Confined-but-Connected Quantum Solids via Controlled Ligand Displacement
Confined-but-Connected Quantum Solids via Controlled Ligand Displacement
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DOI：
10.1021/nl401298s
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发表时间：
2013-07-01
期刊：
影响因子：
10.8
通讯作者：
Hanrath, Tobias
中科院分区：
文献类型：
--
作者：
Baumgardner, William J.;Whitham, Kevin;Hanrath, Tobias
受限但连接的量子点固体（QDS）将可调谐、量子受限能级的优点与通过增强的电子点间耦合实现的高效电荷传输结合起来。我们报道了通过用极性非溶剂处理胶体 PbSe 量子点自组装膜来制造 QDS。用二甲基甲酰胺处理可以平衡自组装和配体置换的速率，从而产生具有立方有序和通过相邻点的面的准外延点间连接的受限但连接的QDS结构。通过结合透射电子显微镜以及广角和小角 X 射线散射来分析 QDS 结构。光谱中的激子吸收特征证实量子限制得以保留。传输测量显示经过处理的薄膜的电导率显着增强
Confined-but-connected quantum dot solids (QDS) combine the advantages of tunable, quantum-confined energy levels with efficient charge transport through enhanced electronic interdot coupling. We report the fabrication of QDS by treating self-assembled films of colloidal PbSe quantum dots with polar nonsolvents. Treatment with dimethylformamide balances the rates of self-assembly and ligand displacement to yield confined-but-connected QDS structures with cubic ordering and quasi-epitaxial interdot connections through facets of neighboring dots. The QDS structure was analyzed by a combination of transmission electron microscopy and wide-angle and small-angle X-ray scattering. Excitonic absorption signatures in optical spectroscopy confirm that quantum confinement is preserved. Transport measurements show significantly enhanced conductivity in treated films