am0c01756_si_001.pdf (2.42 MB)
Hydroxymethyl-Functionalized PEDOT-MeOH:PSS for Perovskite Solar Cells
journal contribution
posted on 2020-04-01, 11:39 authored by Hao Dong, Erjin Zheng, Zhiyin Niu, Xiaoyu Zhang, Yi-Yu Lin, Priyesh Jain, Qiuming YuPoly(hydroxymethylated-3,4-ethylenedioxythiophene):polystyrene
sulfonate (PEDOT-MeOH:PSS) conducting polymers are synthesized and
incorporated in inverted structured perovskite solar cells (PVSCs)
as hole transport materials. The highest occupied molecular orbital
of PEDOT-MeOH is lowered by adding a hydroxymethyl (−MeOH)
functional group to ethylenedioxythiophene (EDOT), and thus, the work
function of PEDOT-MeOH:PSS is increased. Additionally, hydrogen bonding
can be formed among EDOT-MeOH monomers and between EDOT-MeOH monomers
and sulfate groups on PSS, which promotes PEDOT-MeOH chain growth
and enhances PSS doping. The electronic, microstructural, and surface
morphological properties of PEDOT-MeOH:PSS are modified by changing
the amounts of PSS and the ferric oxidizing agent used in the polymerization
and by adding ethylene glycol in the postsynthesis treatment. The
PVSCs based on ethylene-glycol-treated PEDOT-MeOH:PSS overperform
the PVSCs based on commercial PEDOT:PSS because of the better energetic
alignment and the enhancement of PEDOT-MeOH:PSS electrical conductivity.
This work opens the way to develop new hole transport materials for
highly efficient inverted PVSCs.