State Key Laboratory of Surface Physics and Physics Department, Fudan University, Shanghai 200433, People's Republic of China.
Nanotechnology. 2013 Feb 15;24(6):065702. doi: 10.1088/0957-4484/24/6/065702. Epub 2013 Jan 16.
Atomic force microscopy imaging combined with selective chemical etching is employed to quantitatively investigate three-dimensional (3D) composition distributions of single GeSi quantum rings (QRs). In addition, the 3D quantitative composition distributions and the corresponding conductance distributions are simultaneously obtained on the same single GeSi QRs by conductive atomic force microscopy combined with selective chemical etching, allowing us to investigate the correlations between the conductance and composition distributions of single QRs. The results show that the QRs' central holes have higher Ge content, but exhibit lower conductance, indicating that the QRs' conductance distribution is not consistent with their composition distribution. By comparing the topography, composition and conductance profiles of the same single QRs before and after different etching processes, it is found that the conductance distributions of GeSi QRs do not vary with the change of composition distribution. Instead, the QRs' conductance distributions are found to be consistent with their topographic shapes, which can be supposed to be due to the shape determined electronic structures.
原子力显微镜成像结合选择性化学刻蚀被用于定量研究单个锗硅量子环（QR）的三维（3D）成分分布。此外，通过导电原子力显微镜结合选择性化学刻蚀，在相同的单个 GeSi QRs 上同时获得 3D 定量成分分布和相应的电导分布，使我们能够研究单个 QR 的电导和成分分布之间的相关性。结果表明，QR 的中心孔具有更高的 Ge 含量，但表现出更低的电导，这表明 QR 的电导分布与它们的成分分布不一致。通过比较同一单个 QR 在不同刻蚀过程前后的形貌、成分和电导轮廓，发现 GeSi QR 的电导分布并不随成分分布的变化而变化。相反，QR 的电导分布与它们的形貌一致，可以假设这是由于形状决定了电子结构。
