摘要
Fourteen atomically thin two-dimensional graphdiynes composed of hexaethynylbenzene and tetraethynylethene were proposed and investigated using density functional theory. Being different from the traditional graphdiyne, these structures have versatile electronic properties. They can be metals, semimetal, or semiconductors, depending on the coupling patterns and proportions of monomers. One hundred and thirty one one-dimensional nanoribbons cutting from these structures have band gaps larger than 0.4 eV. They have high carrier mobilities. Especially, the hole mobility reaches the order of 105 cm2×V-1×s-1. This is caused by small valence band deformation potential constants and explained by crystal orbital analysis. Both the two-and one-dimensional structures have very small formation energies of 3237 meV per carbon atom. Furthermore, a seamless electronic device composed of theabove metallic electrodes and semiconducting nanoribbon has a high conductance of 11.7 mS and the device can be switched off with gate voltage. These imply that the proposed graphdiynes are good candidates for high speed electronic devices.
Fourteen atomically thin two-dimensional graphdiynes composed of hexaethynylbenzene and tetraethynylethene were proposed and investigated using density functional theory. Being different from the traditional graphdiyne, these structures have versatile electronic properties. They can be metals, semimetal, or semiconductors, depending on the coupling patterns and proportions of monomers. One hundred and thirty one one-dimensional nanoribbons cutting from these structures have band gaps larger than 0.4 eV. They have high carrier mobilities. Especially, the hole mobility reaches the order of 105 cm2×V-1×s-1. This is caused by small valence band deformation potential constants and explained by crystal orbital analysis. Both the two-and one-dimensional structures have very small formation energies of 3237 meV per carbon atom. Furthermore, a seamless electronic device composed of theabove metallic electrodes and semiconducting nanoribbon has a high conductance of 11.7 mS and the device can be switched off with gate voltage. These imply that the proposed graphdiynes are good candidates for high speed electronic devices.
基金
supported by the National Natural Science Foundation of China(No.21203127)
the Scientific Research Base Development Program of the Beijing Municipal Commission of Education
