Enhanced stability and efficiency of perovskite solar cells via bifunctional group passivation with thiosalicylic acid

Stability, as an important factor limiting the practical application of perovskite solar cells, has attracted many scientists. Herein, we introduce a hydrophobic molecule of thiosalicylic acid as a passivator to enhance the device stability. The strategy not only improves the thermal stability and anti-moisture of the perovskite film by double anchoring of functional groups to uncoordinated lead ions and the hydrophobicity of the aromatic ring, but also enhances the electronic properties by removing deep trap states of the perovskite film. Further research on the perovskite solar cells with thiosalicylic acid passivation shows that the efficiency of the device can reach 18.07% and good stability. When stored in the air with a relative humidity of 30% for 15 days, the efficiency can still maintain 89.98% of the initial value. The present work offers a simple and effective strategy in fabrication of stable and efficient perovskite solar cells.