Surface redox engineering of vacuum-deposited NiOx for top-performance perovskite solar cells and modules

Summary

It is arduous to prepare thin charge transport layers (CTLs) of only a few nanometers in thickness for meter-sized products, particularly for commonly used solution processes. Thus, it is desirable to take advantages of both solution-processed perovskites and vacuum-deposited CTLs. Herein, a surface redox engineering (SRE) is proposed for vacuum-deposited NiO_x to make it match with the slot-die-coated perovskite films. Not only does it eliminate the de-wetting problem of perovskite ink, but it also imparts enhanced electronic properties at buried interfaces. Consequently, high-performance PSCs are achieved with amazing stability and outstanding power conversion efficiencies of 23.4% and 21.3% for rigid and flexible devices, respectively. Furthermore, perovskite submodules of area 156 × 156 mm² are successfully assembled with a remarkable PCE of 18.6% along with excellent stability. The SRE provides a strategy to use the advantages of both vacuum-fabricated CTLs with wet-processed perovskites for the development of large-area perovskite modules.