Acetylacetone-TiO_(2) Promoted Large Area Compatible Cascade Electron Transport Bilayer for Efficient Perovskite Solar Cells

In designing efficient perovskite solar cells(PSCs),the selection of suitable electron transport layers(ETLs)is critical to the final device performance as they determine the driving force for selective charge extraction.SnO_(2)nanoparticles(NPs)based ETLs have been a popular choice for PSCs due to superior electron mobility,but their relatively deep-lying conduction band energy levels(ECB)result in substantial potential loss.Meanwhile,TiO_(2)NPs establish favorable band alignment owing to shallower ECB,but their low intrinsic mobility and abundant surface trap sites impede the final performance.For this reason,constructing a cascaded bilayer ETL is highly desirable for efficient PSCs,as it can rearrange energy levels and exploit on advantages of an individual ETL.In this study,we prepare SnO_(2)NPs and acetylacetone-modified TiO_(2)(Acac-TiO_(2))NPs and implement them as bilayer SnO_(2)/Acac-TiO_(2)(BST)ETL,to assemble cascaded energy band structure.SnO_(2)contributes to rapid charge carrier transport from high electron mobility while Acac-TiO_(2)minimizes band-offset and effectively suppresses interfacial recombination.Accordingly,the optimized BST ETL generates synergistic influence and delivers power conversion efficiency(PCE)as high as 23.14%with open-circuit voltage(V_(oc))reaching 1.14 V.Furthermore,the BST ETL is transferred to a large scale and the corresponding mini module demonstrates peak performance of 18.39%PCE from 25 cm^(2)aperture area.Finally,the BST-based mini module exhibit excellent stability,maintaining 83.1%of its initial efficiency after 1000 h under simultaneous 1 Sun light-soaking and damp heat(85℃/RH 85%)environment.

Mixed Cations Enabled Combined Bulk and Interfacial Passivation for Efficient and Stable Perovskite Solar Cells

Here,we report a mixed GAI and MAI(MGM)treatment method by forming a 2D alternating-cation-interlayer(ACI)phase(n=2)perovskite layer on the 3D perovskite,modulating the bulk and interfacial defects in the perovskite films simultaneously,leading to the suppressed nonradiative recombination,longer lifetime,higher mobility,and reduced trap density.Consequently,the devices’performance is enhanced to 24.5%and 18.7%for 0.12 and 64 cm^(2),respectively.In addition,the MGM treatment can be applied to a wide range of perovskite compositions,including MA-,FA-,MAFA-,and CsFAMA-based lead halide perovskites,making it a general method for preparing efficient perovskite solar cells.Without encapsulation,the treated devices show improved stabilities.

Lead chemisorption:Paving the last step for industrial perovskite solar cells

Perovskite solar cells(PSCs)have exhibited impressive performance,achieving a power conversion efficiency(PCE)of 26.1%.However,the water-soluble and toxic nature of lead(Pb)in PSCs hinders their industrialization.Pb chemisorption has emerged as a promising approach to address this issue to prevent Pb leakage and ensure long-term stability.This perspective provides a comprehensive overview of recent advancements in Pb chemisorption in PSCs and discusses the prospects for future developments and challenges in this field.