Energy and Charge Transfer Synergetic Donor-Acceptor Heterostructure 2D-COF in Photovoltaics

The formation of orderly p–n heterojunctions by the wafer-scale alignment of donor (D) and acceptor (A) molecules, important to achieve high photocurrent generation in the organic semiconductor-based organization, remains a challenging topic. Presented herein is a distinctive D–A heterostructure two-dimensional organic covalent framework (2D-COF) as an efficient organic photovoltaic (OPV) film, supported by the triple roles of the binary building blocks in a wafer-scale film growing at the water/oil interface, molecular level morphology control, and the synergistic Forster resonance energy transfer (FRET) and charge-transfer (CT) functions. The achieved D–A heterostructure 2D-COF has a wafer-scale size, efficient spectral response, and effective separation of photogenerated electron–hole pairs, resulting in an efficient photocurrent generation which is much larger than those of reported OPV COF materials. The achievement herein confirms that the marriage of FRET and a CT synergetic D–A heterostructure and an ultrathin 2D-COF film offer unparalleled advantages in OPV.