Electron localization and resonant tunneling in uniform nanocrystalline silicon quantum dot systems

In this paper, we review our recent investigation of the electronic transport in hydrogenated nanocrystalline silicon thin film grown on crystalline silicon substrate. The variable magnetic-field Hall measurements have been applied to extract the separated carrier information about the nc-Si:H, c-Si and their interface, where the formation of two-dimensional electron gas is clearly observed. With a decrease in the temperature, the nc-Si:H thin film shows a transition from the extended state to the band-tail state, together with a positive magneto-conductivity at extremely low temperatures. These results reveal the good uniformity of the quantum dots in the nc-Si:H thin film and the electron localization. Furthermore, we have successfully observed clear step-like and spike-like structures for the electrons resonant tunneling through the quasi-2D and 0D states in the I-V curves of the nc-Si:H/c-Si diode under strong electric field at low temperatures.