In perovskite solar cells (PSCs), defective perovskite (PVK) surface and cliff-like energy offset at interface always slow down the charge extraction; meanwhile, interface ion diffusion causes oxidation of metal electrode, inducing device instability. Here, the in-situ grown two dimensional (2D)-MA3Sb2I9 on back surface of MAPbI3 results in a more robust interface. MA3Sb2I9 changes the MAPbI3 surface to p-type and thus acts like back surface field to drive charge extraction and suppress recombination, resulting in obviously higher fill factor (FF)=0.8 and power conversion efficiency (PCE)= 20.4% of SnO2/MAPbI3/MA3Sb2I9/Spiro-OMeTAD PSC than pure MAPbI3 device. More importantly, strong chemical bonding of Sb-I prohibits ion diffusion, largely enhancing the thermal stability and longtime stability. This work highlights a special 2D-MA3Sb2I9 constructs robust band alignment and chemical environment at the interface for efficient and stable PSCs.

2D-MA3Sb2I9 back surface field for efficient and stable perovskite solar cells

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.