Hydrophobic Fluorinated Conjugated Polymer as a Multifunctional Interlayer for High-Performance Perovskite Solar Cells

It is known that the perovskite/hole transport layer (HTL) interface is a great limit to achieving high-performance perovskite solar cells (PSCs). Aiming to solve this problem, we introduce a naphthalene diimide (NDI)-based conjugated polymer bearing 3,4-difluorothiophene (PTzNDI-2FT) at the perovskite/HTL interface. We find that the PTzNDI-2FT interlayer combines multifunctions to passivate surface defects on the perovskite film, improve charge transport at the perovskite/HTL interface, and prevent penetration of the moisture and organic ion volatilization in the perovskite film. The champion device exhibits a power conversion efficiency of 23.2% under standard AM 1.5 G one sun illumination and offers excellent environmental, heat, and light stabilities.

Automated summary

The introduction of a new conjugated polymer at the perovskite/HTL interface has been shown to enhance the performance of perovskite solar cells. The polymer combines multiple functions to modify the perovskite film, improve charge transport, and prevent the penetration of harmful substances.