Construction of Stable Donor-Acceptor Type Covalent Organic Frameworks as Functional Platform for Effective Perovskite Solar Cell Enhancement

Covalent organic frameworks (COFs) as a new class of crystalline, porous materials have attracted extensive attention in the fields of photocatalytic and photovoltaic applications. Generally, donor-acceptor (DA) structures play an important role in the charge separation efficiency of solar cells. In this study, two DA-COFs with high crystallinity, good porosity, and excellent stability are incorporated into the FAPbI(3) layer of perovskite solar cells. This addition of DA-COFs reduces the defect concentration and shallows the defect state. The donor-acceptor system in COFs also possesses strong charge-transfer pathway, which strongly prevents charge recombination to afford more efficient charge separation efficiency. The highest power-conversion efficiency of perovskite solar cells constructed with DA-COFs is 23.19% with excellent humidity stability of the solar cells. Therefore, this work provides a pathway for using DA-COFs to fabricate perovskite solar cells with higher efficiency and stability.

Automated summary

Covalent organic frameworks (COFs) as a new type of porous materials show great potential in photocatalytic and photovoltaic applications. Incorporating high-crystallinity, porous, and stable donor-acceptor (DA) COFs into perovskite solar cells can reduce defects and improve charge separation efficiency, resulting in higher power-conversion efficiency and humidity stability.