LAUSR

Interface engineering is often necessary in the TiO 2 nanoparticles (NPs) based perovskite solar cells (PVSCs) to facilitate the extraction and transport of charge carriers. In this work, poly[(9,9-bis(3'-(N,N-dimethyl)propyl)-2,7-fluorene)-alt- 2,7-(9,9-dioctylfluorene) (PFN) and polystyrene (PS) are demonstrated to be effective surface modifiers of TiO 2 NPs electron-transporting layer in n-i-p PVSCs. Excitingly, the low-cost insulating polymer PS performs better than the conjugated polymer PFN owing to the high film quality, low surface energy and insulating characteristics. The peak PCE of 15.09% and 17.13% with an ultra-high V OC of 1.18 V is achieved from TiO 2 NPs/PS based PVSCs using hole-transporting material of MEH-PPV and spiro-OMeTAD respectively, which casts light on the commercialization of PVSCs by employing cheap plastics.