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The π-extension of carbon nanorings towards ultrashort carbon nanotubes (CNTs) is a great challenge for synthetic chemists. Herein, we report the synthesis, characterization, and properties of a nanographene-embedded carbon nanoring (NECR) by a direct zipper method. In this approach, a long linear phenyl chain is fused onto the CPP backbone by a simple Scholl reaction, similar to zipping two pieces of fabric together. Its photophysical properties were studied by UV-vis and photoluminescence spectroscopy. The potential application of NECR in electron-transport devices were further investigated. [ABSTRACT FROM AUTHOR]

The performance of organic field-effect transistors (OFETs) is highly dependent on the dielectric–semiconductor interface, especially in ion-gel-gated OFETs, where a significantly high carrier density is induced at the interface at a low gate voltage. This study investigates how altering the alkyl side chain length of donor–acceptor (D-A) copolymers impacts the electrical performance of ion-gel-gated OFETs. Two difluorobenzothiadiazole-based D-A copolymers, PffBT4T-2OD and PffBT4T-2DT, are compared, where the latter features longer alkyl side chains. Although PffBT4T-2DT shows a 2.4-fold enhancement of charge mobility in the SiO2-gated OFETs compared to its counterpart due to higher crystallinity in the film, PffBT4T-2OD outperforms PffBT4T-2DT in the ion-gel-gated OFETs, manifested by an extraordinarily high mobility of 17.7 cm2/V s. The smoother surface morphology, as well as stronger interfacial interaction between the ion-gel dielectric and PffBT4T-2OD, enhances interfacial charge accumulation, which leads to higher mobility. Furthermore, PffBT4T-2OD is blended with a polymeric elastomer SEBS to achieve ion-gel-gated flexible OFETs. The blend devices exhibit high mobility of 8.6 cm2/V s and high stretchability, retaining 45% of initial mobility under 100% tensile strain. This study demonstrates the importance of optimizing the chain structure of polymer semiconductors and the semiconductor–dielectric interface to develop low-voltage and high-performance flexible OFETs for wearable electronics applications. [ABSTRACT FROM AUTHOR]

In this work, planar-heterojunction organic phototransistors (OPT) have been constructed from solution process, by combining a semiconducting diketopyrrolopyrrole polymer PDVT-10 and a novel carbon nano-material-carbon quantum dots (CQDs). The PDVT-10/CQDs planar heterojunction films, possessing the optical properties of both PDVT-10 and CQDs, reveal strong optical absorption in a wide spectral region from ultraviolet to near infra-red. Compared with pristine PDVT-10 phototransistors, such planar-heterojunction OPTs exhibit a remarkably higher performance on broad-spectrum photo-detection, with a photoresponsivity of 2.6 x 104 A/W, a specific detectivity of 2.4 x 1013 Jones, and maximum light sensitivity higher than 104 under the 450-nm laser irradiation, as well as with a responsivity of 4.4x104 A/W and a specific detectivity of 1.2 x1013 Jones under the 808-nm laser irradiation. Based on the study of the photo-response mechanism for these devices, the performance improvement of the PDVT-10/CQDs based OPTs should be attributed to the favorable energy level alignment at the PDVT-10/CQDs interfaces, which enhances interfacial exciton dissociation and charge separation, meanwhile effectively suppresses the hole-electron recombination in the light-absorption layer. Furthermore, the formation of efficient carrier conduction pathway is benefited from high hole-mobility of PDVT-10 for the OPT performance enhancement. Our work offers a valuable avenue for the development of high performance light detectors. [ABSTRACT FROM AUTHOR]