Effects of Anti‐UV UV312 Molecular on Photovoltage Properties of Perovskite Solar Cells

Perovskite solar cells (PSCs) are prone to photodegradation under ultraviolet (UV) irradiation, and the device defects limit their photovoltage property and stability. In the present study, the effects of the UV absorber UV312 as a multifunctional additive on the properties of PSCs have been investigated in detail. It was found that UV312 can effectively filters UV light, significantly reducing photodegradation of the perovskite material. On the other hand, the carbonyl (─C═O) and amino (─NH─) groups in its molecular structure have played a key role, in which the former coordinated with uncoordinated Pb²⁺, while the latter formed hydrogen bonds with iodide ions (I⁻), enabling multisite defect passivation. After the addition of UV312, the power conversion efficiency (PCE) of PSCs was increased from 21.76% to 24.14%. In terms of stability, the unencapsulated devices retained 90% of their initial efficiency after 60 days of storage in air and maintained 75% of their initial PCE after 10 h of continuous UV irradiation. Thus, this study confirmed that UV312 can simultaneously provide UV protection and defect passivation in PSCs, offering an effective strategy for improving both efficiency and operational stability of PSCs.