A Polymer Defect Passivator for Efficient Hole-Conductor-Free Printable Mesoscopic Perovskite Solar Cells

Due to the low cost and excellent potential for mass production, printable mesoscopic perovskite solar cells (p-MPSCs) have drawn a lot of attention among other device structures. However, the low open-circuit voltage (V-OC) of such devices restricts their power conversion efficiency (PCE). This limitation is brought by the high defect density at perovskite grain boundaries in the mesoporous scaffold, which results in severe nonradiative recombination and is detrimental to the V-OC. To improve the perovskite crystallization process, passivate the perovskite defects, and enhance the PCE, additive engineering is an effective way. Herein, a polymeric Lewis base polysuccinimide (PSI) is added to the perovskite precursor solution as an additive. It improves the perovskite crystallinity and its carbonyl groups strongly coordinate with Pb2+, which can effectively passivate defects. Additionally, compared with its monomer, succinimide (SI), PSI serves as a better defect passivator because the long-chained macromolecule can be firmly anchored on those defect sites and form a stronger interaction with perovskite grains. As a result, the champion device has a PCE of 18.84%, and the V-OC rises from 973 to 1030 mV. This study offers a new strategy for fabricating efficient p-MPSCs.

Automated summary

Printable mesoscopic perovskite solar cells (p-MPSCs) have gained attention due to their low cost and potential for mass production. However, their low open-circuit voltage (V-OC) limits their power conversion efficiency (PCE). In this study, a polymeric Lewis base polysuccinimide (PSI) was added to the perovskite precursor solution as an additive to improve perovskite crystallization, passivate defects, and enhance PCE. The fabricated p-MPSCs achieved a champion device with a PCE of 18.84% and an increased V-OC from 973 to 1030 mV, offering a new strategy for efficient p-MPSC fabrication.