摘要

By using nonequilibrium Green's function method in combination with density functional theory, the electron transport properties of single atomic chain connected silicene-silicane or germanene-germanane nanoribbon junction are theoretically investigated. Obvious rectifying behaviors with rectification ratios up to 10(4) can be obtained by asymmetrically hydrogenating electrodes of the nano junctions. The edge pattern of hydrogenated electrode is shown to play a significant role in determining the rectifying direction of these diodes. Besides, the germanium atoms constructed nano diodes show better rectifying performance than the respective devices constructed by silicon atoms. The rectifying mechanism for these devices is elucidated by analyzing the molecular projected self-consistent Hamiltonian, the transmission spectrum and the band structure of electrodes with applied bias.