Perovskite surface management by thiol and amine copper porphyrin for stable and clean solar cells

The leakage of noxious lead and the instability of pemvskite film induced by interfacial defects have impeded the practical application of pemvskite solar cells (PSCs). Here, we develop a pemvskite surface management strategy by the post-treatment with a copper porphyrin containing thiol and secondary amine group (Cu-Por). The thiol-terminal in Cu-Por can coordinate with the Pb defects on the pemvskite surface. The central Cu2+ ions in Cu-Por tune the electron distribution within porphyrin ring, thereby effectively binding the I- and I-2 on the perovskite surface by pi-I interaction and the hydrogen-bonds between the side chain N-H group with I- and I-2. Finally, the Cu-Por-treated PSCs gave the best efficiency of 21.24%. More importantly, the modified device maintained over 90% of its initial efficiency under AM 1.5G illumination or heated at 85 degrees C in N-2 atmosphere after 2000 h. Especially, the Cu-Por treated PSCs can prevent the leakage of lead. This finding provides a new pemvskite surface management strategy to fabricate the stable and clean PSCs.

Automated summary

A surface management strategy using a copper porphyrin compound with thiol and secondary amine groups was developed to prevent lead leakage and improve the efficiency and stability of perovskite solar cells. The compound effectively binds to Pb defects on the perovskite surface and maintains high efficiency under different conditions, providing a new approach for fabricating stable and clean PSCs.