An 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.