Department of Physics, Beijing Normal University, Beijing 100875, China.
ACS Nano. 2010 Jan 26;4(1):91-8. doi: 10.1021/nn9010279.
The electronic structures of the CdSe/CdS core-shell nanorods are systemically investigated by large-scale first-principles quality calculations. The effects of band alignment, quantum confinement, piezoelectric field, and dipole moments are analyzed and delineated by comparing the results of systems with or without some of these attributes. We found complicated interplays between these effects in determining the nanorod band gap and electron hole wave function localizations. The hole wave function is found to be localized inside the CdSe core, while the electron wave function is localized in the CdS shell, with its distance to the CdSe core depending on the surface passivation. The permanent dipole moment induced by different surface passivations can change the electron hole separation, while the piezoelectric effect plays a relatively minor role. Finally, we demonstrate that it is straightforward to manipulate the nanorod electronic structure by changing its CdSe core position.
通过大规模的第一性原理质量计算，系统地研究了 CdSe/CdS 核壳纳米棒的电子结构。通过比较具有或不具有这些属性的系统的结果，分析和描绘了能带排列、量子限制、压电场和偶极矩的影响。我们发现，这些效应在确定纳米棒带隙和电子空穴波函数局域化方面存在复杂的相互作用。空穴波函数被发现局域在 CdSe 核内，而电子波函数局域在 CdS 壳内，其距离 CdSe 核的位置取决于表面钝化。不同表面钝化引起的永久偶极矩可以改变电子空穴分离，而压电效应的作用相对较小。最后，我们证明通过改变 CdSe 核的位置，可以很方便地操纵纳米棒的电子结构。
