We studied the thermoelectric properties of a diketopyrrolopyrrole-based semiconductor (PDPP3T) via a precisely tuned doping process using Iron (III) chloride. In particular, the doping states of PDPP3T film were linearly controlled depending on the dopant concentration. The outstanding Seebeck coefficient of PDPP3T assisted the excellent power factors (PFs) over 200 μW m−1K−2 at the broad range of doping concentration (3–8 mM) and the maximum PF reached up to 276 μW m−1K−2, which is much higher than that of poly(3-hexylthiophene), 56 μW m−1K−2. The high-mobility of PDPP3T was beneficial to enhance the electrical conductivity and the low level of total dopant volume was important to maintain high Seebeck coefficients. In addition, the low bandgap PDPP3T polymer effiectively shifted its absorption into near infra-red area and became more colorless after doping, which is great advantage to realize transparent electronic devices. Our results give importance guidance to develop thermoelectric semiconducting polymers and we suggest that the use of low bandgap and high-mobility polymers, and the accurate control of the doping levels are key factors for obtaining the high thermoelectric PF.

Highly ordered organic semiconductor micropatterns of the liquid-crystalline small molecule 2,7-didecylbenzothienobenzothiophene (C10 -BTBT) are fabricated using a simple method based on template-assisted self-assembly (TASA). The liquid crystallinity of C10 -BTBT allows solvent-free fabrication of high-performance printed organic field-effect transistors (OFETs).

The use of 3-dimensional (3D) printable conductive materials has gained significant attention for various applications because of their ability to form unconventional geometrical architectures that cannot be realized with traditional 2-dimensional printing techniques. To resolve the major requisites in printed electrodes for practical applications (including high conductivity, 3D printability, excellent adhesion, and low-temperature processability), we have designed a chemically-reinforced multi-dimensional filler system comprising amine-functionalized carbon nanotubes, carboxyl-terminated silver nanoparticles, and Ag flakes, with the incorporation of a thermoplastic polystyrene-polyisoprene-polystyrene (SIS) triblock copolymer. It is demonstrated that both high conductivity, 22 939 S cm, and low-temperature processability, below 80 °C, are achievable with the introduction of chemically anchored carbon-to-metal hybrids and suggested that the highly viscous composite fluids employing the characteristic thermoplastic polymer are readily available for the fabrication of various unconventional electrode structures by a simple dispensing technique. The practical applicability of the 3D-printable highly conductive composite paste is confirmed with the successful fabrication of wireless power transmission modules on substrates with extremely uneven surface morphologies.

The development of sulfur cathodes with high areal capacity and high energy density is crucial for the practical application of lithium-sulfur batteries (LSBs). LSBs can be built by employing (ultra) high-loading sulfur cathodes, which have rarely been realized due to massive passivation and shuttling.Herein, microspheres of a carbon-carbon nitride composite (C@CN) with large mesopores are fabricated via molecular cooperative assembly. Using the C@CN-based electrodes, the effects of the large mesopores and N-functional groups on the electrochemical behavior of sulfur in LSB cells are thoroughly investigated under ultrahigh sulfur-loading conditions (>15 mg S cm −2 ). Furthermore, for high-energy-density LSBs, the C@CN powders are pelletized into a thick free-standing electrode (thickness: 500 μm; diameter: 11 mm) via a simple briquette process; here, the total amount of energy stored by the LSB cells is 39 mWh, corresponding to a volumetric energy density of 440 Wh L −1 with an areal capacity of 24.9 and 17.5 mAh cm −2 at 0.47 and 4.7 mA cm −2 , respectively (at 24 mg S cm −2 ). These results have significantly surpassed most recent records due to the synergy among the large mesopores, (poly)sulfidephilic surfaces, and thick electrodes. The developed strategy with its potential for scale-up successfully fills the gap between laboratory-scale cells andThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Lithium-sulfur batteries (LSBs) have emerged as promising power sources for high-performance devices such as electric vehicles. However, the poor energy density of LSBs owing to polysulfide shuttling and passivation has limited their further market penetration. To mitigate this challenge, two-dimensional (2D) siloxene (2DSi), a Si-based analog of graphene, is utilized as an additive for sulfur cathodes. The 2DSi is fabricated on a large scale by simple solvent extraction of calcium disilicide to form a thin-layered structure of Si planes functionalized with vertically aligned hydroxyl groups in the 2DSi. The stoichiometric reaction of 2DSi with polysulfides generates a thiosulfate redox mediator, secures the intercalation pathway, and reveals Lewis acidic sites within the siloxene galleries. The 2DSi utilizes the corresponding in-situ-formed electrocatalyst, the 2D confinement effect of the layered structure, and the surface affinity based on Lewis acid-base interaction to improve the energy density of 2DSi-based LSB cells. Combined with the commercial carbon-based current collector, 2DSi-based LSB cells achieve a volumetric energy density of 612 Wh L cell −1 at 1 mA cm −2 with minor degradation of 0.17% per cycle, which rivals those of state-of-the-art LSBs.This study presents a method for the industrial production of high-energydense LSBs.