Graphene Interface Engineering for Perovskite Solar Modules: 12.6% Power Conversion Efficiency over 50 cm2 Active Area

Interfaces between perovskite solar cell (PSC) layer components play a pivotal role in obtaining high-performance premium cells and large-area modules. Graphene and related twodimensional materials (GRMs) can be used to "on-demand" tune the interface properties of PSCs. We successfully used GRMs to realize large-area (active area 50.6 cm(2)) perovskite-based solar modules (PSMs), achieving a record high power conversion efficiency of 12.6%. We on-demand modulated the photoelectrode charge dynamic by doping the mesoporous TiO2 (mTiO(2)) layer with graphene flakes. Moreover, we exploited lithium-neutralized graphene oxide flakes as interlayer at the mTiO(2)/perovskite interface to improve charge injection. Notably, prolonged aging tests have shown the long-term stability for both small- and large area devices using graphene-doped mTiO(2). Furthermore, the possibility of producing and processing GRMs in the form of inks opens a promising route for further scale-up and stabilization of the PSM, the gateway for the commercialization of this technology.