Isolated flat bands and physics of mixed dimensions in a 2D covalent organic framework

摘要: We demonstrate that it is possible to rationally incorporate both an isolated flat band and the physics of zero dimensions (0D), one dimension (1D), two (2D) in a single 2D material. Such unique electronic properties are present recently synthesized covalent organic framework (COF), where “I”-shaped building blocks “T”-shaped connectors result quasi-1D chains linked by quasi-0D bridge units arranged stable lattice. The lowest unoccupied conduction band, electron-doping gives rise novel quantum phenomena, such as magnetism Mott insulating phases. highest occupied valence arises from wave functions chains. Examples mixed dimensional illustrated this system. strong electron–hole asymmetry material results large Seebeck coefficient, while nature leads linear dichroism, conjunction with strongly bound excitons. elucidate strategies design optimize COFs host bands quantum-confined 1D subsystems. COF discussed here provide taste intriguing possibilities open research field.