Two-dimensional materials in perovskite solar cells

In the broad contest of halide perovskite solar cells (PSCs), interfaces play a meaningful role by ruling the efficiency and stability of devices.To decouple interface requirements from the bulk material properties, interface layers have been considered and successfully applied to improve solar cell performances.In this perspective, we analyze the use of two-dimensional (2D) materials such as graphene and related compounds as intra and inter layer in PSCs.A vast library of two-dimensional materials is nowadays available that allows for interface and work function engineering necessary for an effective optimization of solar cells.In addition, 2D materials can limit the ion diffusion, layer-by-layer degradation and moisture induce decomposition of perovskite, improving considerably the PSCs' stability.Their use is not only limited to lab-scale devices but it has been successful extended to large area perovskite modules, as well as to perovskite/silicon tandem cell, paving the way for an industrial exploitation of such 2D strategy.