Negative differential resistance and tunable peak-to-valley ratios in a silicon nanochain

The current-voltage characteristics of a silicon nanochain is investigated. The nanochain is viewed as a superlattice structure of quantum dots (QDs), where silicon cores in a chain act as QDs while silicon dioxides covering the cores act as potential barriers. It is found that the whole nanochain structure can display the negative differential conductance (NDC) feature as the tunneling current through each barrier has the NDC property individually. Importantly, large peak-to-valley ratios of the current are observed and tunable by the number of QDs involved. This feature will be useful in device design. © 2008 American Institute of Physics.