Minimalist Design of Efficient, Stable Perovskite Solar Cells.

Feasible production process and excellent device stability are significant prerequisites for the practical application of perovskite solar cells (PSCs). Herein, a systemic strategy is developed to fabricate stable, minimalist PSCs without a conventional electron/hole transport layer. The engineering is carried out by surface modification of the fluorine-doped tin oxide (FTO) substrate and incorporation of perovskite film with NiO nanoparticles (NPs). Notably, the surface modification can impart an unexpected porous structure to the FTO substrate, thereby facilitating efficient diffusion and deposition of perovskite. Besides, the incorporated NiO NPs passivate the defects of perovskite film, resulting in the increase of perovskite grain size, decrease of grain boundary density, and increase of film thickness. Synergistic improvements in film quality and interfacial contact enhance charge transport/extraction capacity and suppress electron/hole recombination. Consequently, the stabilized efficiency of 14.65% is realized for this modified FTO/MAPbI3-NiO/Ag device, with excellent moisture and thermal stability. Overall, this work provides a viable strategy for accelerating the commercialization of PSCs due to the significant process simplification and cost reduction.