Van der Waals Effects on semiconductor clusters
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2015-08-12 |
| Journal | Journal of Computational Chemistry |
| Authors | Haisheng Li, Weiguang Chen, Xiaoyu Han, Liben Li, Qiang Sun |
| Institutions | University College London, Henan University of Science and Technology |
| Citations | 5 |
Abstract
Section titled āAbstractāVan der Waals (vdW) interactions play an important role on semiconductors in nanoscale. Here, we utilized firstāprinciples calculations based on density functional theory to demonstrate the growth mode transition from prolate to multiunit configurations for Ge n ( n = 10-50) clusters. In agreement with the injected ion drift tube techniques that āclusters with n < 70 can be thought of as loosely bound assemblies of small strongly bound fragments (such as Ge 7 and Ge 10 ),ā we found these stable fragments are connected by Ge 6 , Ge 9 , or Ge 10 unit (from bulk diamond), via strong covalent bonds. Our calculated cations usually fragment to Ge 7 and Ge 10 clusters, in accordance with the experiment results that the spectra Ge 7 and Ge 10 correspond to the mass abundance spectra. By controlling a germanium cluster with vdW interactions parameters in the program or not, we found that the vdW effects strengthen the covalent bond from different units more strikingly than that in a single unit. With more bonds between units than the threadlike structures, the multiunit structures have larger vdW energies, explaining why the isolated nanowires are harder to produce. Ā© 2015 Wiley Periodicals, Inc.