Development of Pyr-TPA as Interfacial Passivation Layer Enabling Efficient and Stable n-i-p Perovskite Solar Cells

Interfacial passivation is a crucial technique for improving the performance of perovskite solar cells (PSCs) by suppressing nonradiative recombination. Incorporating electron-rich functional groups into organic semiconductors can combine the advantages of Lewis bases and organic semiconductors to achieve defect passivation of perovskite films and interfacial charge transport improvement simultaneously. However, interlayers generated by organic semi- conductors are often destroyed during the deposition of the hole transport layer (HTL) in n-i-p PSCs. This prevents the accurate evaluation of interfacial pas- sivation effects. Herein, a pyromellitic derivative, 2,6-bis(4-(bis(4-methoxyphenyl) amino)phenyl)pyrrolo[3,4-f]isoindole-1,3,5,7(2 H,6 H)-tetraone (Pyr-TPA), containing four carbonyl groups that can passivate defects and enhance hole transport while simultaneously acting as a stable interlayer at the perovskite/HTL interface due to its ideal solubility profile is introduced. As a result, Pyr-TPA as an interlayer can minimize nonradiative recombination loss, resulting in a power conversion efficiency of up to 24.16%. Additionally, the interfacial Pyr-TPA passivation layer also exhibits strong resistance to moisture and ion migration, leading to enhanced long-term ambient stability of PSCs based on this material. Findings provide valuable insights into developing efficient and stable PSCs with simple and effective organic semiconductor interfacial passivation materials.