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Organic photodetectors (OPDs) have received great interest for their tremendous potential in the field of optical communication, medical monitoring and intelligent buildings. Interface layers are commonly introduced between the electrodes and active layer of OPDs, to facilitate charge extraction and increase reverse charge injection, thus achieving low dark current density (Jd) and high specific detectivity (D*). However, high preparation cost and hygroscopicity of the interface layer limit their further development in practical applications. Herein, we report a direct modification strategy of the indium tin oxide (ITO) anode to construct high-performance OPDs. The ITO anode modified by dilute hydrochloric acid (ITO-Cl) increases the work function and surface hydrophobicity of the substrate due to the surface coverage of Cl atoms. Using ITO-Cl as the anode, the shifted work function increases the electron injection barrier from the anode to the active layer and the enhanced surface hydrophobicity induces a more favorable vertical stratification morphology of the active layer deposited on the anode surface. As a direct consequence, the OPD device based on the ITO-Cl anode exhibits an ultra-low Jd of 0.90 nA cm−2 at −1 V bias and high peak D* of 2.31 × 1012 cm Hz1/2 W−1 (or 1.79 × 1013 cm Hz1/2 W−1 calculated from the shot noise), which is superior to the control device based on traditional anode ITO/poly(3,4-ethylenedioxythiophene):poly-styrene sulfonate (PEDOT:PSS) due to the effective reduction of the dark current. These results demonstrated that the ITO chlorination strategy is a competitive candidate for developing high-performance OPDs. [ABSTRACT FROM AUTHOR]

Linear conjugated polymers have attracted significant attention in organic electronics in recent decades. However, despite intrachain π‐delocalization, interchain hopping is their transport bottleneck. In contrast, two‐dimensional (2D) conjugated polymers, as represented by 2D π‐conjugated covalent organic frameworks (2D c‐COFs), can provide multiple conjugated strands to enhance the delocalization of charge carriers in space. Herein, we demonstrate the first example of thiophene‐based 2D poly(arylene vinylene)s (PAVs, 2DPAV‐BDT‐BT and 2DPAV‐BDT‐BP, BDT=benzodithiophene, BT=bithiophene, BP=biphenyl) via Knoevenagel polycondensation. Compared with 2DPAV‐BDT‐BP, the fully thiophene‐based 2DPAV‐BDT‐BT exhibits enhanced planarity and π‐delocalization with a small band gap (1.62 eV) and large electronic band dispersion, as revealed by the optical absorption and density functional calculations. Remarkably, temperature‐dependent terahertz spectroscopy discloses a unique band‐like transport and outstanding room‐temperature charge mobility for 2DPAV‐BDT‐BT (65 cm2 V−1 s−1), which far exceeds that of the linear PAVs, 2DPAV‐BDT‐BP, and the reported 2D c‐COFs in the powder form. This work highlights the great potential of thiophene‐based 2D PAVs as candidates for high‐performance opto‐electronics. [ABSTRACT FROM AUTHOR]

Background: Transaxillary endoscopic thyroidectomy (TAET) is favored for its favorable cosmetic outcomes and the preservation of anterior cervical function. Despite these benefits, postoperative analgesia has traditionally relied on pharmacological interventions, and regional anesthetic procedures may be an alternative method. This study aimed to evaluate the efficacy of an ultrasound-guided pectoserratus plane block (PSPB) combined with an intermediate cervical plexus block (ICPB) for TAET., Methods: Forty patients undergoing TAET were randomized into two groups: the nerve block group (N.=20) received ultrasound guided PSPB with 20 ml of 0.375% ropivacaine and ICPB with 8 mL of 0.3% ropivacaine, while the control group (N.=20) received no block. The primary outcome was the Visual Analog Scale (VAS) scores for postoperative neck and axillary pain at different time points (1, 6, 12, 24 h) during rest and movement post-TAET. The secondary outcomes included intraoperative remifentanil consumption, incidence of postoperative nausea and vomiting (PONV), number of remedial analgesic requirements, and patient satisfaction postoperatively., Results: Compared to the control group, patients in the nerve block had significantly lower VAS scores of the neck and axilla whether at rest or movement, and 1, 6, 12, and 24 h postoperatively (P<0.0125). The nerve block group showed higher patient satisfaction (P<0.001). No difference was observed in intraoperative remifentanil consumption, need for rescue analgesics, or other adverse effects 48 h postoperatively., Conclusions: Ultrasound-guided PSPB with ICPB significantly alleviated postoperative pain and improved patient satisfaction with TAET.

Linear conjugated polymers have attracted significant attention in organic electronics in recent decades. However, despite intrachain π-delocalization, interchain hopping is their transport bottleneck. In contrast, two-dimensional (2D) conjugated polymers, as represented by 2D π-conjugated covalent organic frameworks (2D c-COFs), can provide multiple conjugated strands to enhance the delocalization of charge carriers in space. Herein, we demonstrate the first example of thiophene-based 2D poly(arylene vinylene)s (PAVs, 2DPAV-BDT-BT and 2DPAV-BDT-BP, BDT=benzodithiophene, BT=bithiophene, BP=biphenyl) via Knoevenagel polycondensation. Compared with 2DPAV-BDT-BP, the fully thiophene-based 2DPAV-BDT-BT exhibits enhanced planarity and π-delocalization with a small band gap (1.62 eV) and large electronic band dispersion, as revealed by the optical absorption and density functional calculations. Remarkably, temperature-dependent terahertz spectroscopy discloses a unique band-like transport and outstanding room-temperature charge mobility for 2DPAV-BDT-BT (65 cm 2  V -1  s -1 ), which far exceeds that of the linear PAVs, 2DPAV-BDT-BP, and the reported 2D c-COFs in the powder form. This work highlights the great potential of thiophene-based 2D PAVs as candidates for high-performance opto-electronics., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

Sequence-defined synthetic oligomers and polymers provide unprecedented opportunities for polymer chemists to finely control properties such as chain folding, self-assembly, and optoelectronic performance of materials. However, absolute control over both chain-length and monomer sequence has been a long-standing "grand challenge" for decades. Herein, we report a novel strategy to synthesize monodisperse sequence-defined conjugated oligomers in a homogeneous manner by temperature cycling, thereby achieving single-monomer precision in conjugated polyheterocycles. A series of sequence-defined oligomers with up to twelve repeating units, four different monomers, and various sequences were successfully synthesized. Monomer sequence was also proved to affect optical properties. We believe this strategy not only exhibits general applicability to the synthesis of group 16 conjugated oligomers and polymers, but also has far-reaching potential for other polymer systems., (© 2022 Wiley-VCH GmbH.)

We report 4,4-difluoro-4H-cyclopenta[2,1-b:3,4-b']dithiophene (fCDT) as a new electron-rich unit to design polymer electron acceptors. Owing to the fluoro substitutes, fCDT unit exhibits downshifted LUMO energy level, diminished steric hindrance effect and strong intermolecular interaction. The resulting polymer electron acceptor exhibits low-lying LUMO energy level and high electron mobility, as well as good all-polymer solar cell device performance., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)