Enhanced Device Performances of MAFACsPb(IxBr1-x) Perovskite Solar Cells with Dual-Functional 2-Chloroethyl Acrylate Additives

Perovskite photovoltaics (PePVs) tend to suffer from a high density of detects that restrict the device in terms of performances and stability. Therefore, defect passivation and film-quality improvement of perovskite active layers are crucial for high-performance PePVs. In this work, 2-chloroethyl acrylate (CEA) with C=O and -CI groups in Cs(0.175)FA(0)(.7)(30)MA(0.075)Pb (I0.880Br0.120) precursor solutions is introduced as a novel bifunctional additive to act as both a defect passivator and perovskite-growth controller. With the aid of CEA, the perovskite crystallinity and average grain size are improved, and perovskite defects are effectively reduced, thus increasing the representative efficiency (PCE = 19.32%). PePVs with CEA also maintain their initial efficiency of 85% even after about 500 h under air conditions with a humidity of 40 +/- 5%. As a result, this study proves that the novel additive CEA can produce higher PePV efficiency and more stable devices.