2 research outputs found
Cross Self-n-Doping and Electron Transfer Model in a Stable and Highly Conductive Fullerene Ammonium Iodide: A Promising Cathode Interlayer in Organic Solar Cells
Self-n-doped stable and highly conductive
fullerene ammoniums with
excellent thickness-tolerance
could act as promising cathode interlayers to facilitate electron
transfer and improve power conversion efficiencies (PCEs) of large-area
organic solar cells (OSCs). Herein, systematic studies on electronic
and spatial structure of fullerene ammonium iodide (PCBANI) have been
performed to elucidate the cross self-n-doping mechanism. In PCBANI,
partial electron transfer from iodide to the core fullerene could
result in n-doping and high conductivity. This doping process forms
strong anion-Ï€ interactions between iodides and fullerene cores
accompanied by side-chain’s head-to-tail cation-π interactions
that contribute to the stabilization of the n-doped fullerene. Moreover,
two possible pathways of the cross self-n-doping involving intermolecular
exchange and transfer of iodide have been verified by experiment combined
with computational modeling. Based on all of the solid evidence, we
propose an electron transfer model for PCBANI in which the iodide
sandwiched in the n-doped fullerene core acts as a shuttle to transfer
electrons via redox processes. This finding provides a strategy for
electrically doping and assembling fullerenes to improve their performance
in photovoltaic devices and endow them with new functionalities that
could be applied to optoelectronics and organic electronics
Separation of Hydrogen Gas from Coal Gas by Graphene Nanopores
We designed a series of porous graphene
as the separation membrane
for hydrogen gas in coal gas. The permeation process of different
gas molecules (H<sub>2</sub>, CO, CH<sub>4</sub>, and H<sub>2</sub>S) in porous graphene was evaluated under the atmospheric pressure
and high pressure conditions. Our results indicate the hydrogen permeability
and selectivity could be tuned by the size and the shape of the porous
graphene. For graphene with bigger pores, the selectivity for hydrogen
gas could decrease. In the porous graphene with same pore area, the
hydrogen gas selectivity could be affected by the shape of the pore.
The potential of mean force (PMF) of different gases to pass through
a good separation candidate was calculated. The order of PMF for different
gases to pass through the good separation candidate is H<sub>2</sub> < CO < CH<sub>4</sub> ≈ H<sub>2</sub>S, which is also
confirmed by the first-principle density function theory (DFT) calculation