6 research outputs found
3-Methyl 5-{3-[(4-Methylbenzenesulfonyl)oxy]propyl} 4-(2,3-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
The 1,4-dihydropyridine is a ubiquitous scaffold employed not only in medicinal chemistry but also in organic synthesis, given its ability to act as a hydrogen transfer reagent, thus emulating NAD(P)H reducing agents. In this work, we describe the synthesis of 3-methyl 5-{3-[(4-methylbenzenesulfonyl)oxy]propyl} 4-(2,3-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate as scaffold, which enables downstream derivatization towards new 1,4-dihydropyridine molecules. Inspired by the literature, a new two-step synthesis was planned that involved: (i) synthesis of a silylated 1,4-dihydropyridine derivative and (ii) deprotection and tosylation in one step using tosyl fluoride
Surface Modulation via Conjugated Bithiophene Ammonium Salt for Efficient Inverted Perovskite Solar Cells
The metal halide perovskite absorbers are prone to surface defects, which severely limit the power conversion efficiencies (PCEs) and the operational stability of the perovskite solar cells (PSCs). Herein, trace amounts of bithiophene propylammonium iodide (bi-TPAI) are applied to modulate the surface properties of the gas-quenched perovskite. It is found that the bi-TPAI surface treatment has negligible impact on the perovskite morphology, but it can induce a defect passivation effect and facilitate the charge carrier extraction, contributing to the gain in the open-circuit voltage (Voc) and fill factor. As a result, the PCE of the gas-quenched sputtered NiOx-based inverted PSCs is enhanced from the initial 20.0% to 22.0%. Most importantly, the bi-TPAI treatment can largely alleviate or even eliminate the burn-in process during the maximum power point tracking measurement, improving the operational stability of the devices
Surface Modulation via Conjugated Bithiophene Ammonium Salt for Efficient Inverted Perovskite Solar Cells
The
metal halide perovskite absorbers are prone to surface
defects,
which severely limit the power conversion efficiencies (PCEs) and
the operational stability of the perovskite solar cells (PSCs). Herein,
trace amounts of bithiophene propylammonium iodide (bi-TPAI) are applied
to modulate the surface properties of the gas-quenched perovskite.
It is found that the bi-TPAI surface treatment has negligible impact
on the perovskite morphology, but it can induce a defect passivation
effect and facilitate the charge carrier extraction, contributing
to the gain in the open-circuit voltage (Voc) and fill factor. As a result, the PCE of the gas-quenched sputtered
NiOx-based inverted PSCs is enhanced from
the initial 20.0% to 22.0%. Most importantly, the bi-TPAI treatment
can largely alleviate or even eliminate the burn-in process during
the maximum power point tracking measurement, improving the operational
stability of the devices
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Tailoring Interlayer Charge Transfer Dynamics in 2D Perovskites with Electroactive Spacer Molecules
The family of hybrid organic-inorganic lead-halide perovskites are the subject of intense interest for optoelectronic
applications, from light-emitting diodes to photovoltaics to X-ray detectors. Due to the inert nature of most organic
molecules, the inorganic sublattice generally dominates the electronic structure and therefore optoelectronic properties of
perovskites. Here, we use optically and electronically active carbazole-based Cz-Ci molecules, where Ci indicates an alkylammonium
chain and i indicates the number of CH2 units in the chain, varying from 3−5, as cations in the 2D perovskite
structure. By investigating the photophysics and charge transport characteristics of (Cz-Ci)2PbI4, we demonstrate a tunable
electronic coupling between the inorganic lead-halide and organic layers. The strongest interlayer electronic coupling was
found for (Cz-C3)2PbI4, where photothermal deflection spectroscopy results remarkably demonstrate an organic-inorganic
charge transfer state. Ultrafast transient absorption spectroscopy measurements demonstrate ultrafast hole transfer from
the photoexcited lead-halide layer to the Cz-Ci molecules, the efficiency
of which increases by varying the chain length from i=5 to
i=3. The charge transfer results in long-lived carriers (10–100 ns)
and quenched emission, in stark contrast with the fast (sub-ns)
and efficient radiative decay of bound excitons in the more conventional
2D perovskite (PEA)2PbI4, in which phenylethylammonium
(PEA) acts as an inert spacer. Electrical charge transport
measurements further support enhanced interlayer coupling,
showing increased out-of-plane carrier mobility from i=5 to i=3.
This study paves the way for the rational design of 2D perovskites
with combined inorganic-organic electronic properties through
the wide range of functionalities available in the world of organics
Recommended from our members
Tailoring Interlayer Charge Transfer Dynamics in 2D Perovskites with Electroactive Spacer Molecules.
The family of hybrid organic-inorganic lead-halide perovskites are the subject of intense interest for optoelectronic applications, from light-emitting diodes to photovoltaics to X-ray detectors. Due to the inert nature of most organic molecules, the inorganic sublattice generally dominates the electronic structure and therefore the optoelectronic properties of perovskites. Here, we use optically and electronically active carbazole-based Cz-Ci molecules, where Ci indicates an alkylammonium chain and i indicates the number of CH2 units in the chain, varying from 3 to 5, as cations in the two-dimensional (2D) perovskite structure. By investigating the photophysics and charge transport characteristics of (Cz-Ci)2PbI4, we demonstrate a tunable electronic coupling between the inorganic lead-halide and organic layers. The strongest interlayer electronic coupling was found for (Cz-C3)2PbI4, where photothermal deflection spectroscopy results remarkably reveal an organic-inorganic charge transfer state. Ultrafast transient absorption spectroscopy measurements demonstrate ultrafast hole transfer from the photoexcited lead-halide layer to the Cz-Ci molecules, the efficiency of which increases by varying the chain length from i = 5 to i = 3. The charge transfer results in long-lived carriers (10-100 ns) and quenched emission, in stark contrast to the fast (sub-ns) and efficient radiative decay of bound excitons in the more conventional 2D perovskite (PEA)2PbI4, in which phenylethylammonium (PEA) acts as an inert spacer. Electrical charge transport measurements further support enhanced interlayer coupling, showing increased out-of-plane carrier mobility from i = 5 to i = 3. This study paves the way for the rational design of 2D perovskites with combined inorganic-organic electronic properties through the wide range of functionalities available in the world of organics
Tailoring Interlayer Charge Transfer Dynamics in 2D Perovskites with Electroactive Spacer Molecules
The family of hybrid organic–inorganic lead-halide
perovskites
are the subject of intense interest for optoelectronic applications,
from light-emitting diodes to photovoltaics to X-ray detectors. Due
to the inert nature of most organic molecules, the inorganic sublattice
generally dominates the electronic structure and therefore the optoelectronic
properties of perovskites. Here, we use optically and electronically
active carbazole-based Cz-Ci molecules,
where Ci indicates an alkylammonium chain
and i indicates the number of CH2 units
in the chain, varying from 3 to 5, as cations in the two-dimensional
(2D) perovskite structure. By investigating the photophysics and charge
transport characteristics of (Cz-Ci)2PbI4, we demonstrate a tunable electronic coupling
between the inorganic lead-halide and organic layers. The strongest
interlayer electronic coupling was found for (Cz-C3)2PbI4, where photothermal deflection spectroscopy
results remarkably reveal an organic–inorganic charge transfer
state. Ultrafast transient absorption spectroscopy measurements demonstrate
ultrafast hole transfer from the photoexcited lead-halide layer to
the Cz-Ci molecules, the efficiency of
which increases by varying the chain length from i = 5 to i = 3. The charge transfer results in long-lived
carriers (10–100 ns) and quenched emission, in stark contrast
to the fast (sub-ns) and efficient radiative decay of bound excitons
in the more conventional 2D perovskite (PEA)2PbI4, in which phenylethylammonium (PEA) acts as an inert spacer. Electrical
charge transport measurements further support enhanced interlayer
coupling, showing increased out-of-plane carrier mobility from i = 5 to i = 3. This study paves the way
for the rational design of 2D perovskites with combined inorganic–organic
electronic properties through the wide range of functionalities available
in the world of organics