The luminescent and photophysical properties of covalent organic frameworks

Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers that have attracted significant attention due to their tunable properties and structural robustness. As a result, COFs with luminescent properties are of great interest for fields such as chemical sensing, solid-state light emitters, photocatalysis, and optoelectronics. However, the bottom-up synthesis of luminescent COF systems remains a challenge in the field due to an abundance of competing non-radiative pathways, including phenomena such as aggregate caused quenching (ACQ). To overcome these obstacles, there has been a burgeoning investigation into the luminescent and photophysical properties of COFs. This review will highlight methods used to fabricate luminescent COFs and discuss the factors that are critical for their production. A collection of known luminescent COF systems will be featured. In addition, the ability to utilize the photophysical properties of COFs for applications related to photocatalysis, solid-state light emitters, and chemical sensing will be addressed. An outlook will address the current progress and remaining challenges facing the field to ultimately expand the scope of their applications.