锗硅半导体量子电库仑荷电效应的研究

The study of quantum dot structure of semiconductor material has attracted significant interest both from the point of view of fundamental condense matter physics and for information technological applications. In this project, the quantum confinement and Coulomb charge effect have been studied and obtained valuable results as following:1．The Coulomb charge effect in SiGe quantum dot studied by admittance spectroscopy.Quantum confined energy levels and the Coulomb charging effect of holes in self-assembled Ge dots embedded in Si barriers are studied using dmittance spectroscopy at temperatures above 100 K. Ground state and first excited state are identified by varying the Fermi-level position under different applied bias voltages in the admittance measurements. Hole-capture cross sections of the quantum levels are found to be extremely large and energy dependent. 2..DLTS measurement is used to study the carrier capturing process. The capture and the emission of the holes in the Ge quantum dot can be controlled by the position of the Fermi level with the variance of the reverse bias voltage and the filling pulse oltage. Hole capture process and Coulomb charging effect have also been observed by the DLTS measurements with various pulse widths. The hole-tunneling model is proposed by comparing the DLTS spectra of single layer quantum dot and double layer quantum dot. The experiment results are confirmed by the computer-simulation.

制备锗硅量子点以形成"人造原子"基"人造分子",探索用空间电荷谱技术检测量子点中的量幽芗?并研究在量子点内部及量子点之间的库仑荷电效应对量子能级的影响,以及在强磁场饔孟碌牧孔幽芗兜姆至?开展对半导体量子点的试验和理论研究,将会有助于推动量子力理鄣姆⒄购屯晟?