Semiconducting covalent organic frameworks: a type of two-dimensional conducting polymers

In recent years, as a new class of two-dimensional polymer, covalent organic frameworks (COFs) have attracted intensive attention and developed rapidly. This review provides an overview of a type of COFs which can be utilized as organic semiconductors. Carefully choosing monomers as the building blocks will bestow different types of semiconducting character on COFs. We summarize the p-type, n-type and ambipolar semiconducting COFs and highlight the effects of π-functional building blocks on the photoconductive behaviors of the semiconducting COFs.