Printed hole-conductor-free mesoscopic perovskite solar cells with excellent long-term stability using PEAI as an additive

Phenethylamine（PEA） was successfully introduced into hole-conductor-free, fully printable mesoscopic MAPbI3 perovskite solar cells（MPSCs） with a carbon electrode by mixing phenethylammonium iodide with MAPbI3 perovskite solution. PEA-MAPbI3 films show better pore filling into TiO2 scaffold that forms better contact, and induce longer exciton lifetime and higher quantum efficiency of photoinduced charge separation. As a result, the power conversion efficiency of PEA-MAPbI3 MPSCs is 37% higher than that of MAPbI3 MPSCs. And PEA-MAPbI3 MPSCs show excellent long-term stability that could keep 90% of origin power conversion efficiency for over 80 days in the air.

Influence of precursor concentration on printable mesoscopic perovskite solar cells

Over the last decade,the power conversion efficiency of hybrid organic-inorganic perovskite solar cells(PSCs)has increased dramatically from 3.8%to 25.2%.This rapid progress has been possible duc to the accurate control of the morphology and crystallinity of solution-processed perovskites,which are significantly affected by the concentration of the precursor used.This study explores the influence of precursor concentrations on the performance of printable hole-conductor-free meso-scopic PSCs via a simple one-step drop-coating method.The results reveal that lower concentrations lead to larger grains with inferior pore flling,while higher concentra-tions result in smaller grains with improved pore filling.Among concentrations ranging from 0.241.20M,devices based on a moderate strength of 0.70M were confirmed to exhibit the best efficiency at 16.32%.

Highly oriented MAPbI3 crystals for efficient hole-conductor-free printable mesoscopic perovskite solar cells

Highly crystalline perovskite films with large grains and few grain boundaries are conducive for efficient and stable perovskite solar cells.Current methods for preparing perovskite films are mostly based on a fast crystallization process,with rapid nucleation and insufficient growth.In this study,MAPbI3 perovskite with inhibited nucleation and promoted growth in the TiO_(2)/ZrO_(2)/carbon triple mesoscopic scaffold was crystallized by modulating the precursor and the crystallization process.N-methylformamide showed high solubility for both methylammonium iodide and Pbl2 and hampered the formation of large colloids in the MAPbI3 precursor solution.Furthermore,methylammonium chloride was added to reduce large colloids,which are a possible source of nucleation sites.During the crystallization of MAPbI3,the solvent was removed at a slow controlled speed,to avoid rapid nucleation and provide sufficient time for crystal growth.As a result,highly oriented MAPbI3 crystals with suppressed non-radiative recombination and promoted charge transport were obtained in the triple mesoscopic layer with disordered pores.The corresponding hole-conductor-free,printable mesoscopic perovskite solar cells exhibited a highest power conversion efficiency of 18.82%.The device also exhibited promising long-term operational sta-bility of 1000 h under continuous illumination at maximum power point at 55±5°C and damp-heat stability of 1340 h aging at 85°C as well as 85%relative humidity.