Fig. 1: Molecular structure of PDMEA and interaction mechanism of PDMEA with PEI and Ag layers.

a Schematic illustration of p-i-n PSC and molecular mechanism. b Photographs of PEI, PDMEA and PEI + PDMEA solutions respectively. c FTIR spectra of the PEI, PDMEA and PEI + PDMEA solutions respectively. d FTIR spectra of the PDMEA and Ag/PDMEA films respectively. e, f Ag 3 d (e) and S 2p (f) XPS spectra of the Ag and Ag/PDMEA films.