摘要
Electrical properties of individual self-assembled GeSi quantum dots grown on Si substrates are investigated by using conductive atomic force microscopy at room temperature. By controlling the bias voltage sweep in a certain fast sweep rate range, a novel current peak is observed in the current-voltage characteristics of the quantum dots. The current peaks are detectable only during the backward voltage sweep immediately after a forward sweep. The current peak position and intensity are found to depend strongly on the voltage sweep conditions. This kind of current-voltage characteristic under fast sweep is very different from the ordinary steady state current behaviour of quantum dots measured previously. trapping in the potential well formed bottom Si substrate. The origin of this phenomenon by the quantum dot sandwiched can be attributed to the transient hole between the native oxide layer and the
Electrical properties of individual self-assembled GeSi quantum dots grown on Si substrates are investigated by using conductive atomic force microscopy at room temperature. By controlling the bias voltage sweep in a certain fast sweep rate range, a novel current peak is observed in the current-voltage characteristics of the quantum dots. The current peaks are detectable only during the backward voltage sweep immediately after a forward sweep. The current peak position and intensity are found to depend strongly on the voltage sweep conditions. This kind of current-voltage characteristic under fast sweep is very different from the ordinary steady state current behaviour of quantum dots measured previously. trapping in the potential well formed bottom Si substrate. The origin of this phenomenon by the quantum dot sandwiched can be attributed to the transient hole between the native oxide layer and the
基金
Supported by the National Natural Science Foundation of China under Grant Nos 60425411 and 10874030, the National Basic Research Programme of China under Grant No 2006CB921505, and Shanghai Science and Technology Commission.
