Cascaded Charge-Transfer Organic Alloys for the Controlled Hierarchical Self-Assembly of Low-Dimensional Heterostructures

Abstract

Organic alloys integrating intrinsic alloys characters and organic semiconductor advantages demonstrate the multi-component synergistic and collective effects for possessing more desirable structural or functional properties. However, their finely rational design and the controlled self-assembly of their corresponding heterostructure materials remain yet to be explored. Herein, we successfully fabricated the novel organic CT alloys with tunable energy structures and the hierarchical heterostructures via a self-assembly process of the cascade CT interaction, which is rationally designed by finely regulating the weak electron donation and affinity of isomorphic 1,2,4,5-tetracyanobenzene (TCNB)-based CT complexes. The high chemical/structural compatibility between isomorphic CT complexes and their alloys is conducive to the excellent lattice matching requirement for the precise preparation of the triblock or core/shell-type organic heterostructures via the sequential or stepwise self-assembly processes. Impressively, these as-prepared organic heterostructures achieve the controlled exciton conversion and the tunable active/passive photon propagation modes, benefiting for the optical logic gate with nanoscale multiple input/out. Significantly, this strategy could be generalized to other organic CT alloys and hierarchical heterostructures, affording fresh comprehension to materials foundation for integrated optoelectronics.

Keywords: Charge-transfer interactions, Organic alloys, Hierarchical self-assembly, Low-dimensional heterostructures, Organic cocrystal