10.1021/acs.jpcc.8b04931.s001
Christopher
S. Kerr
Christopher
S.
Kerr
Artem Kryukovskiy
Artem
Kryukovskiy
Jennifer I. L. Chen
Jennifer
I. L. Chen
Effects of Surface Passivation on Trap States, Band
Bending, and Photoinduced Charge Transfer in P3HT/TiO<sub>2</sub> Hybrid
Inverse Opals
American Chemical Society
2018
polymer
framework
TiO 2 nanoparticles
photoinduced charge transfer
TiCl 4
polaron
P 3HT 2 Hybrid Inverse Opals
TiO 2 passivation reagent
Photoinduced Charge Transfer
unpassivated P 3HT 2
metal oxide
opal
2018-07-12 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Effects_of_Surface_Passivation_on_Trap_States_Band_Bending_and_Photoinduced_Charge_Transfer_in_P3HT_TiO_sub_2_sub_Hybrid_Inverse_Opals/6847463
We
investigate the effect of a common TiO<sub>2</sub> passivation
reagent, TiCl<sub>4</sub>, on the photoinduced charge transfer of
poly(3-hexylthiophene) (P3HT) to TiO<sub>2</sub> in the inverse opal
structure. Treating the inorganic oxide framework with TiCl<sub>4</sub> leads to an increase in the size of the TiO<sub>2</sub> nanoparticles,
a thickening of the inverse opal framework, and a decrease in the
trap-state photoluminescence. These changes lead to different energy
alignments at the interface. In comparison to the unpassivated P3HT/TiO<sub>2</sub> inverse opal, we measured a larger polaron yield, by as high
as ninefold, and significantly shorter and more uniformly distributed
polaron lifetimes in TiCl<sub>4</sub>-treated samples. We show that
downward band bending in the polymer can be circumvented by tuning
the trap states on the metal oxide using TiCl<sub>4</sub>, thereby
eliminating the energetic barrier for photoelectron injection from
the polymer to the metal oxide. The findings suggest a way to overcome
a potential factor that has plagued the performance of metal oxide–polymer
hybrid photovoltaics.