Experimental (FTIR and FT-Raman) and theoretical investigation of some pyridine-dicarboxylic acids

Synergistic passivation with multi-dentate 2,6-pyridinedicarboxylic acid for high-performance perovskite solar cells

“…2(c)) were observed at 1704 and 1579 cm −1 , respectively. 41 These stretching vibrations were also observed in MAPbI 3 /2,6-PDA, although the corresponding peak positions were shifted to 1695 and 1570 cm −1 , proving that both the carboxylic and pyridyl groups were interacting with the uncoordinated Pb 2+ defects in the MAPbI 3 film, 42 healing the positively charged trap states. The –OH stretching vibration of 2,6-PDA emerged at 3408 cm −1 , which was shifted to 3398 cm −1 in MAPbI 3 /2,6-PDA (Fig.…”