Additive Engineering for High-Performance Inverted Large-Area Perovskite Solar Modules

Commercialization of perovskite solar cells (PSCs) urgently needs to scale up to modules. Therefore, improving the device performance of large-area perovskite solar cell modules (PSMs) is of great significance. Here, we used the 4-Chlorobenzoicacid (4-CBA) as an additive to improve the power conversion efficiency (PCE) and stability of inverted (p-i-n) PSMs. A strong Lewis acid-base interaction between the acetate group $(\mathbf{Ac}^{-})$ of 4-CBA and $\mathbf{Pb}^{2+}$ in perovskite is of great benefit to enlarge the grain size of perovskite and reduce carrier recombination, thereby improving the quality of large-area perovskite films. As a result, the introduction of 4-CBA boosts the PCE from 9.66% to 15.08% for 57.3 $\mathbf{cm}^{2}$ (active area) $\mathbf{NiO}_{\mathrm{x}}$ -based PSMs. More importantly, the PSMs with 4-CBA demonstrate excellent humidity stability, which can retain 95% of their initial efficiency after being kept for 30 days under ambient air conditions. This work provides guidance for the large-scale manufacture of PSCs.