N‐type conjugated polymers as the semiconducting component of organic electrochemical transistors (OECTs) are still undeveloped with respect to their p‐type counterparts. Herein, we report two rigid ...n‐type conjugated polymers bearing oligo(ethylene glycol) (OEG) side chains, PgNaN and PgNgN, which demonstrated an essentially torsion‐free π‐conjugated backbone. The planarity and electron‐deficient rigid structures enable the resulting polymers to achieve high electron mobility in an OECT device of up to the 10−3 cm2 V−1 s−1 range, with a deep‐lying LUMO energy level lower than −4.0 eV. Prominently, the polymers exhibited a high device performance with a maximum dimensionally normalized transconductance of 0.212 S cm−1 and the product of charge‐carrier mobility μ and volumetric capacitance C* of 0.662±0.113 F cm−1 V−1 s−1, which are among the highest in n‐type conjugated polymers reported to date. Moreover, the polymers are synthesized via a metal‐free aldol‐condensation polymerization, which is beneficial to their application in bioelectronics.
Two new n‐type semiconducting polymers, PgNaN and PgNgN, bearing oligo(ethylene glycol) (OEG) side chain are developed with a fully conformationally locked backbone and deep‐lying LUMO energy level. As a result, the polymer of PgNaN exhibits a good performance on OECT devices with a maximum dimensionally normalized transconductance of 0.212 S cm−1 and a product μC* of 0.662±0.113 F cm−1 V−1 s−1.
Complexes made by hosts that completely surround their guests provide a means to stabilize reactive chemical intermediates, transfer biologically active cargo to a diseased cell, and construct ...molecular‐scale devices. By the virtue of inorganic host–guest self‐assembly, nucleation processes in the cavity of a {P8W48}‐archetype phosphotungstate has afforded a nanoscale 16‐AlIII‐32‐oxo cluster and its GaIII analogue that contain the largest number of AlIII/GaIII ions yet found in polyoxometalate (POM) chemistry. Interestingly, the rich Lewis acid AlIII centers within the Lewis base POM support shows an exceptional proton conductivity of 4.5×10−2 S cm−1 (85 °C, 70 % RH; RH: relative humidity), which is by far the highest conductivity reported among POM‐based single‐crystal proton conductors.
Guest house: Host–guest self‐assembly of the wheel‐shaped {P8W48} phosphotungstate with strong Lewis acid centers resulted in polyoxometalates (POMs) containing the largest AlIII‐oxo and GaIII‐oxo clusters. The enhanced proton conductivity of the AlIII derivative arises from the synergistic effect imposed by the rich Lewis acid–base pairs as well as acidic nitrate functions.
Three n-type fused lactam semiconducting polymers were synthesized for thermoelectric and transistor applications via a cheap, highly atom-efficient, and nontoxic transition-metal free aldol ...polycondensation. Energy level analysis of the three polymers demonstrated that reducing the central acene core size from two anthracenes (
), to mixed naphthalene-anthracene (
), and two naphthalene cores (
) resulted in progressively larger electron affinities, thereby suggesting an increasingly more favorable and efficient solution doping process when employing 4-(2,3-dihydro-1,3-dimethyl-1
-benzimidazol-2-yl)-
,
-dimethylbenzenamine (N-DMBI) as the dopant. Meanwhile, organic field effect transistor (OFET) mobility data showed the
and
polymers to feature the highest charge carrier mobilities, further highlighting the benefits of aryl core contraction to the electronic performance of the materials. Ultimately, the combination of these two factors resulted in
,
, and
to display power factors (PFs) of 3.2 μW m
K
, 1.6 μW m
K
, and 0.3 μW m
K
, respectively, when doped with N-DMBI, whereby the PFs recorded for
and
are among the highest reported in the literature for n-type polymers. Importantly, the results reported in this study highlight that modulating the size of the central acene ring is a highly effective molecular design strategy to optimize the thermoelectric performance of conjugated polymers, thus also providing new insights into the molecular design guidelines for the next generation of high-performance n-type materials for thermoelectric applications.
Four solution-processable, linear conjugated polymers of intrinsic porosity are synthesised and tested for gas phase carbon dioxide photoreduction. The polymers' photoreduction efficiency is ...investigated as a function of their porosity, optical properties, energy levels and photoluminescence. All polymers successfully form carbon monoxide as the main product, without the addition of metal co-catalysts. The best performing single component polymer yields a rate of 66 μmol h
m
, which we attribute to the polymer exhibiting macroporosity and the longest exciton lifetimes. The addition of copper iodide, as a source of a copper co-catalyst in the polymers shows an increase in rate, with the best performing polymer achieving a rate of 175 μmol h
m
. The polymers are active for over 100 h under operating conditions. This work shows the potential of processable polymers of intrinsic porosity for use in the gas phase photoreduction of carbon dioxide towards solar fuels.
Abstract
A set of unique features, including large-area solution processing on flexible and stretchable substrates, make polymer semiconductors a promising material choice for a range of ...state-of-the-art applications in electronics, optoelectronics and sensing. Yet, an inherent weakness of polymer semiconductors remains their low dielectric constants, increasing their susceptibility toward unscreened dipoles. These dipoles are particularly prevalent at polymer-dielectric interfaces with high-
k
dielectrics, which are essential for the operation of devices such as low-voltage field-effect transistors. This shortcoming can be addressed by using self-assembled monolayers (SAMs) to passivate surfaces that impact charge transport. However, SAM-treatment also increases the hydrophobicity of surfaces and therefore poses a challenge for subsequent solution processing steps and complex packaging of devices. Here, we report low-voltage polymer transistors processed by spin coating of the polymer semiconductors on highly hydrophobic SAM-treated aluminum and hafnium oxide dielectrics (contact angles >100) through fine-tuning of the interfacial tension at the polymer-dielectric interface. This approach enables the processing and detailed characterization of near-amorphous (indacenodithiophene-
co
benzothiadiazole) as well as semicrystalline (
poly(2,5-bis(2-octyldodecyl)-3,6-di(thiophen-2-yl)diketopyrrolo3,4-cpyrrole-1,4-dione-alt-thieno3,2-bthiophen
)) polymer semiconductors. We demonstrate polymer transistors that exhibit high on-currents and field-independent, charge carrier mobilities of 0.8 cm
2
V
−1
s
−1
at low operating voltages (<3 V).
Complexes made by hosts that completely surround their guests provide a means to stabilize reactive chemical intermediates, transfer biologically active cargo to a diseased cell, and construct ...molecular‐scale devices. By the virtue of inorganic host–guest self‐assembly, nucleation processes in the cavity of a {P8W48}‐archetype phosphotungstate has afforded a nanoscale 16‐AlIII‐32‐oxo cluster and its GaIII analogue that contain the largest number of AlIII/GaIII ions yet found in polyoxometalate (POM) chemistry. Interestingly, the rich Lewis acid AlIII centers within the Lewis base POM support shows an exceptional proton conductivity of 4.5×10−2 S cm−1 (85 °C, 70 % RH; RH: relative humidity), which is by far the highest conductivity reported among POM‐based single‐crystal proton conductors.
Saure Gäste: Die Wirt‐Gast‐Assemblierung des radförmigen {P8W48}‐Phosphowolframats mit stark Lewis‐sauren Zentren führt zu Polyoxometallaten (POMs) mit den bisher größten AlIII‐ und GaIII‐Oxoclustern. Die erhöhte Protonenleitfähigkeit der AlIII‐Derivate wird durch den synergistischen Effekt der reichhaltigen Lewis‐Säure/Base‐Paare mit den sauren Nitratfunktionen hervorgerufen.
Novel p-type semiconducting polymers that can facilitate ion penetration, and operate in accumulation mode are much desired in bioelectronics. Glycol side chains have proven to be an efficient method ...to increase bulk electrochemical doping and optimize aqueous swelling. One early polymer which exemplifies these design approaches was p(g2T-TT), employing a bithiophene-co-thienothiophene backbone with glycol side chains in the 3,3′ positions of the bithiophene repeat unit. In this paper, the analogous regioisomeric polymer, namely pgBTTT, was synthesized by relocating the glycol side chains position on the bithiophene unit of p(g2T-TT) from the 3,3′ to the 4,4′ positions and compared with the original p(g2T-TT). By changing the regio-positioning of the side chains, the planarizing effects of the S–O interactions were redistributed along the backbone, and the influence on the polymer’s microstructure organization was investigated using grazing-incidence wide-angle X-ray scattering (GIWAXS) measurements. The newly designed pgBTTT exhibited lower backbone disorder, closer π-stacking, and higher scattering intensity in both the in-plane and out-of-plane GIWAXS measurements. The effect of the improved planarity of pgBTTT manifested as higher hole mobility (μ) of 3.44 ± 0.13 cm2 V–1 s–1. Scanning tunneling microscopy (STM) was in agreement with the GIWAXS measurements and demonstrated, for the first time, that glycol side chains can also facilitate intermolecular interdigitation analogous to that of pBTTT. Electrochemical quartz crystal microbalance with dissipation of energy (eQCM-D) measurements revealed that pgBTTT maintains a more rigid structure than p(g2T-TT) during doping, minimizing molecular packing disruption and maintaining higher hole mobility in operation mode.
Three lactone‐based rigid semiconducting polymers were designed to overcome major limitations in the development of n‐type organic thermoelectrics, namely electrical conductivity and air stability. ...Experimental and theoretical investigations demonstrated that increasing the lactone group density by increasing the benzene content from 0 % benzene (P‐0), to 50 % (P‐50), and 75 % (P‐75) resulted in progressively larger electron affinities (up to 4.37 eV), suggesting a more favorable doping process, when employing (N‐DMBI) as the dopant. Larger polaron delocalization was also evident, due to the more planarized conformation, which is proposed to lead to a lower hopping energy barrier. As a consequence, the electrical conductivity increased by three orders of magnitude, to achieve values of up to 12 S cm and Power factors of 13.2 μWm−1 K−2 were thereby enabled. These findings present new insights into material design guidelines for the future development of air stable n‐type organic thermoelectrics.
Three new n‐type semiconducting polymers, P‐0, P‐50, and P‐75 are developed, in which the lactone group densities were maximized by increasing the benzene content from 0 % benzene (P‐0), to 50 % (P‐50), and 75 % (P‐75), to enable co‐planar polymers with deep‐lying LUMO energy level. As a result, the polymer of P‐75 exhibits a good thermoelectric performance with a maximum electrical conductivity of 12 S cm‐1 and figure of merit power factor of 13.2 μWm‐1 K‐2.
Proton‐Conducting POMs. In their Communication on page 13046 ff. N. M. Khashab et al. prepare wheel‐shaped {P8W48} polyoxometalates (POMs) containing the largest AlIII‐oxo clusters and having ...enhanced proton conductivity.
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