Orbital occupation in electron-charged CdSe quantum-dot solids
Orbital occupation in electron-charged CdSe quantum-dot solids
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DOI：
10.1021/jp053103i
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发表时间：
2005-10-27
影响因子：
3.3
通讯作者：
Vanmaekelbergh, D
中科院分区：
文献类型：
--
作者：
Houtepen, AJ;Vanmaekelbergh, D
我们制备了高质量的单分散CdSe量子点组件，并采用电化学门控和电学和光学技术相结合的方法研究了这些量子点固体中的轨道占用。电子在局域态的占据在某些情况下是重要的，并且可以明确地与纳米晶体本征态的占据区分开来。此外，由于电子电荷的存在，所有的激子跃迁都表现出跃迁能量的红移。我们推断S电子的能量是由量子约束能量和S电子与组装体中所有其他电子的库仑斥力决定的。通过使用一个简单的电子排斥模型，我们解释了不同样品中观察到的电子附加能的差异，电子占位的拓宽作为电化学电位的函数，以及电子附加能与纳米晶体直径的强烈依赖。
We have prepared high-quality assemblies of monodisperse CdSe quantum dots and employed a combination of electrochemical gating and electrical and optical techniques to study orbital occupation in these quantum-dot solids. Electron occupation in localized states is important in some cases and can be unambiguously distinguished from occupation of the nanocrystal eigenstates. In addition, all excitonic transitions show a red-shift in the transition energy, due to the presence of electron charge. We infer that the energy of the S electrons is determined by the quantum-confinement energy and by Coulomb repulsions of the S electron with all other electrons in the assembly. By using a simple electron-repulsion model, we explain observed differences in the electron-addition energy for different samples, the broadening of the electron occupation as a function of electrochemical potential, and the strong dependence of the electron-addition energy on nanocrystal diameter.