Fig. 1: The synthetic route of TPPC and characterizations of the interaction between TPPC and perovskite.

a Synthetic route of TPPC. b The electrostatic potential distribution and dipole moment of TPPC. The structural models and adsorption energies (Eads) of C60 (c) and TPPC (d) on the perovskite surfaces. e 1H-NMR spectra of TPPC and TPPC+SnI2 dissolved in DMSO-d6 solution. High-resolution XPS spectra of I 3 d (f) and Sn 3 d (g) for pristine and TPPC-treated perovskite films.