Interface tweaking of perovskite solar cells with carbon nitride-based 2D materials

Two-dimensional van der Waals layered materials display strong Coulomb interactions, which in turn give rise to large exciton binding energies. Tuning the interface is the basis of devices including optoelectrical, and their delineation is of paramount importance. The developed 2D-carbon nitrides, display graphene-like atomic structures, and the variation in synthetic protocols impact their properties. Engineering the interface with carbon nitride at hole transport layers and perovskite, can eliminate defective charge build-up and suppress the charge carrier recombination rate to induce accelerated photo-induced charge transfer. The fabricated solar cells with L-C₃N₄ or g-C₃N₄ interface layers gave an improved performance with boosted open-circuit voltage and fill factor. The developed interface layers avoid the direct contact of NiO_x with perovskite, overcoming the possible instability of the active layer via iodide oxidation and deprotonation of cationic amines. The carbon nitride-based 2D materials will serve as an effective interfacial layer for long-term reliability in photovoltaics.