Performance enhancement of solution processed perovskite solar cells incorporating functionalized silica nanoparticles

High efficiency, solution processed organic inorganic trihalide perovskite solar cells are now a reality, meaning that perovskite photovoltaics have the potential to challenge more established photovoltaic technologies. To date, some of the most efficient solution processed perovskite solar cells feature a pre-deposited Al2O3 scaffold and we have shown in a previous communication, that it is possible to make efficient devices by co-depositing the Al2O3 nanoparticles with the perovskite precursor solution. In this work, we have substituted the alumina nanoparticles with 3-aminopropyl (3-oxobutanoic acid) functionalized silica nanoparticles (f-SiO2). We observe performance enhancements in planar heterojunction (PHJ) devices made with up to 0.75 wt% f-SiO2 nanoparticles present in the precursor solution, yielding power conversion efficiencies (PCE) of up to 12.4%, compared to the maximum PCE of 10.5% in the equivalent PHJ devices made without f-SiO2 nanoparticles. The performance enhancement arises in part from an average increase to V-OC by up to 50 mV when the nanoparticles are present in the precursor solution and is attributed to substrate passivation within pinholes formed in the perovskite film during processing.