Groupe de Physique des Matériaux UMR CNRS 6634, Normandie Université, Université-INSA de Rouen , Avenue de l'Université BP 12, 76801 Saint Etienne du Rouvray, France.
Nano Lett. 2014 Nov 12;14(11):6066-72. doi: 10.1021/nl502715s. Epub 2014 Oct 3.
Three-dimensional dielectric nanostructures have been analyzed using field ion microscopy (FIM) to study the electric dc field penetration inside these structures. The field is proved to be screened within a few nanometers as theoretically calculated taking into account the high-field impact ionization process. Moreover, the strong dc field of the order of 0.1 V/Å at the surface inside a dielectric nanostructure modifies its band structure leading to a strong band gap shrinkage and thus to a strong metal-like optical absorption near the surface. This metal-like behavior was theoretically predicted using first-principle calculations and experimentally proved using laser-assisted atom probe tomography (APT). This work opens up interesting perspectives for the study of the performance of all field-effect nanodevices, such as nanotransistor or super capacitor, and for the understanding of the physical mechanisms of field evaporation of dielectric nanotips in APT.
使用场离子显微镜 (FIM) 分析了三维介电纳米结构，以研究这些结构内部的直流电场穿透。理论计算表明，考虑到高场碰撞离化过程，电场在几纳米范围内被屏蔽。此外，介电纳米结构内部表面处高达 0.1 V/Å 的强直流电场会改变其能带结构，导致能带隙强烈收缩，从而在表面附近产生强烈的类金属光学吸收。这种类金属行为是通过第一性原理计算进行理论预测，并通过激光辅助原子探针断层扫描 (APT) 实验证明的。这项工作为研究所有场效应纳米器件（如纳米晶体管或超级电容器）的性能以及理解 APT 中介电纳米尖端的场蒸发物理机制开辟了有趣的前景。
