State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433, China.
Nanoscale Res Lett. 2012 May 31;7(1):278. doi: 10.1186/1556-276X-7-278.
The conductive properties of individual self-assembled GeSi quantum dots (QDs) are investigated by conductive atomic force microscopy on single-layer (SL) and bi-layer (BL) GeSi QDs with different dot densities at room temperature. By comparing their average currents, it is found that the BL and high-density QDs are more conductive than the SL and low-density QDs with similar sizes, respectively, indicating the existence of both vertical and lateral couplings between GeSi QDs at room temperature. On the other hand, the average current of the BL QDs increases much faster with the bias voltage than that of the SL QDs does. Our results suggest that the QDs' conductive properties can be greatly regulated by the coupling effects and bias voltages, which are valuable for potential applications.
通过室温下对具有不同点密度的单层 (SL) 和双层 (BL) GeSi 量子点进行导电原子力显微镜研究，研究了单个自组装 GeSi 量子点 (QD) 的导电性能。通过比较它们的平均电流，发现 BL 和高密度 QD 比具有相似尺寸的 SL 和低密度 QD 分别具有更好的导电性，这表明在室温下 GeSi QD 之间存在垂直和横向耦合。另一方面，BL QD 的平均电流随偏压的增加比 SL QD 快得多。我们的结果表明，QD 的导电性能可以通过耦合效应和偏压来进行极大的调控，这对于潜在的应用具有重要意义。
