title: Semiconducting and conducting transition of covalent-organic polymers induced by defects.
abstract: The chemical doping method is often adopted to obtain metal-free conducting materials. To date, it is still a great challenge to controllably prepare metal-free semiconducting and conducting materials by tuning the inherent structure of a material. In this work, a class of novel one-dimensional (1D) covalent-organic polymer (COP) has been designed, whose cross-sections are triangular, tetragonal, pentagonal and hexagonal, and their electronic properties are explored. The tetragonal 1D COP exhibits unique phenomena in electronic properties, i.e. the tetragonal COPs with mono- or trilayer defects (odd defects) show semiconducting properties, while they become conductors for the two cases of non- or bilayer defects (even defects). This observation indicates that they comply with the characteristics of semiconducting and conducting switches induced by the odd-even defects. Therefore, we infer that for the tetragonal configuration, the odd-even defects could potentially manipulate the electrical behavior of the COP material. The discovery provides a new direction for the targeted synthesis of semiconducting and conducting materials by tuning the inherent structure of materials, which is entirely different from the chemical doping method yielding metal-free conducting materials.
authors.affiliation: Division of Molecular and Materials Simulation, State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Huang
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Xiang
authors.forename: Daojian
authors.initials: D
authors.lastname: Cheng
authors.forename: Jianhui
authors.initials: J
authors.lastname: Lan
authors.forename: Wenchuan
authors.initials: W
authors.lastname: Wang
authors.forename: Teng
authors.initials: T
authors.lastname: Ben
authors.forename: Dapeng
authors.initials: D
authors.lastname: Cao
mesh_terms: D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D012666:Semiconductors
chemical_list: D037742:Nanotubes, Carbon; D011108:Polymers