The electronic conduction mechanism of hydrogenated nanocrystalline silicon films

The hydrogenated nano-crystalline silicon films (nc-Si:H) were prepared by using the ultra-high vaccum PECVD system. The nc-Si:H films consist of a mass of nano-grains and a great deal of interfaces between grains. It was found that the room temperature conductivity of nc-Si:H is in the range of 10/sup -3//spl sim/10/sup 0/ (Q/spl middot/cm)/sup -1/, which is higher than that of intrinsic crystalline silicon. In this paper, the two-phase random composite model was used to calculate the conductivities of crystalline grains and interface of nc-Si:H films. The results show that the high conductivity of nc-Si:H arises from the contribution of the crystalline grains. Based on the experimental and calculating results the conduction model of nc-Si:H films is proposed.