No abstract

Two anthracene‐based star‐shaped conjugated small molecules, 5′,5″‐(9,10‐bis((4‐hexylphenyl)ethynyl)anthracene‐2,6‐diyl)bis(5‐hexyl‐2,2′‐bithiophene), HBantHBT, and 5′,5″‐(9,10‐bis(phenylethynyl)anthracene‐2,6‐diyl)bis(5‐hexyl‐2,2′‐bithiophene), BantHBT, are used as electron‐cascade donor materials by incorporating them into organic photovoltaic cells prepared using a poly((5,5‐E‐alpha‐((2‐thienyl)methylene)‐2‐thiopheneacetonitrile)‐alt‐2,6‐[(1,5‐didecyloxy)naphthalene])) (PBTADN):[6,6]‐phenyl‐C71‐butyric acid methyl ester (PC71BM) blend. The small molecules penetrate the PBTADN:PC71BM blend layer to yield complementary absorption spectra through appropriate energy level alignment and optimal domain sizes for charge carrier transfer. A high short‐circuit current (JSC) and fill factor (FF) are obtained using solar cells prepared with the ternary blend. The highest photovoltaic performance of the PBTADN:BantHBT:PC71BM blend solar cells is characterized by a JSC of 11.0 mA cm−2, an open circuit voltage (VOC) of 0.91 V, a FF of 56.4%, and a power conversion efficiency (PCE) of 5.6% under AM1.5G illumination (with a high intensity of 100 mW−2). The effects of the small molecules on the ternary blend are investigated by comparison with the traditional poly(3‐hexylthiophene) (P3HT):[6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) system.

No abstract

Here we describe the use of photocurable poly(vinyl cinnamate) (PVCN) as a gate dielectric in highperformance cylindrical organic field-effect transistors (OFETs) with high bending stability. A smoothsurface metallic fiber (Al wire) was employed as a cylindrical substrate, and polymer dielectrics (PVCN and poly(4-vinyl phenol) (PVP)) were formed via dip-coating. The PVCN and PVP dielectrics deposited on the Al wire and respectively cross-linked via UV irradiation and thermal heating were found to be very smooth and uniform over the entire coated area. Pentacene-based cylindrical OFETs with the polymer dielectrics exhibited high-performance hysteresis-free operation. Devices made with the PVCN dielectric showed superior bending stability than devices made with PVP dielectrics or previously reported cylindrical OFETs due to the good flexibility of the PVCN dielectric. The devices maintained their excellent performance under bending at a bending radius comparable to the lowest value reported for planar OFETs.

A facile spin-coating method in which a small percentage of the solvent additive, 1-chloronaphthalene (CN), is found to increase the drying time during film deposition, is reported. The field-effect mobility of a PDPPDBTE film cast from a chloroform-CN mixed solution is 0.46 cm(2) V(-1) s(-1). The addition of CN to the chloroform solution facilitates the formation of highly crystalline polymer structures.

The receptor material (OA-GO)/polymeric semiconductor (F8T2) structure is newly introduced to active layer of OFET gas sensors and demonstrated to have better sensing ability than a comparable device with a polymer-only active layer.

Immune deficiency (IMD) is a death domain-containing protein that is essential for the IMD/NF-κB humoral and epithelial immune responses to Gram-negative bacteria and viruses in insects. In the immune signaling cascade, IMD is recruited together with FADD and the caspase DREDD after the mobilization of PGRP receptors. Activated IMD regulates the expression of effector antimicrobial peptides (AMP) that protect against invading microorganisms. To date, most studies of the IMD pathway, and the IMD gene in particular, have been restricted to Drosophila; few similar studies have been conducted in other model insects. Herein, we cloned and functionally characterized an IMD homolog from the mealworm beetle Tenebrio molitor ( Tm IMD) and studied its role in host survival in the context of pathogenic infections. Phylogenetic analysis revealed the conserved caspase cleavage site and inhibitor of apoptosis (IAP)-binding motif (IBM). TmIMD expression was high in the hemocytes and Malpighian tubules of Tenebrio late-instar larvae and adults. At 3 and 6 hours’ post-infection with Escherichia coli , Staphylococcus aureus , or Candida albicans , TmIMD expression significantly increased compared with mock-infected controls. Knockdown of the TmIMD transcript by RNAi significantly reduced host resistance to the Gram-negative bacterium E . coli and fungus C . albicans in a survival assay. Strikingly, the expression of nine T. molitor AMPs (Tm Tenecin1 , Tm Tenecin2 , Tm Tenecin4 , Tm Defensin2 , Tm Coleoptericin1 , Tm Coleoptericin2 , Tm Attacin1a , Tm Attacin1b , and Tm Attacin2 ) showed significant downregulation in TmIMD knockdown larvae challenged with E . coli . These results suggest that Tm IMD is required to confer humoral immunity against the Gram-negative bacteria, E . coli by inducing the expression of critical transcripts that encode AMPs.

A series of three thiophene–naphthalene‐based asymmetric oligomers—5‐decyl‐2,2′:5′,2′′:5′′,2′′′‐quaterthiophene (DtT), 5‐decyl‐5′′‐(naphthalen‐2‐yl)‐2,2′:5′,2′′‐terthiophene (D3TN), and 5‐(4‐decylphenyl)‐5′‐(naphthalen‐2‐yl)‐2,2′‐bithiophene (DP2TN)—was synthesized by Suzuki cross‐coupling reactions. The long alkyl side chains improved both the solubility of the oligomers in solvents and their tendency to self‐assemble. UV/Vis absorption measurements suggested that DtT, D3TN, and DP2TN form H‐type aggregates with a face‐to‐face packing structure. In addition, the three oligomers were found to adopt vertically aligned crystalline structures in films deposited on substrates, as revealed by grazing‐incidence wide‐angle X‐ray scattering. These oligomers were used as the active layers of p‐type organic field‐effect transistors, and the resulting devices showed field‐effect mobilities of 3.3×10−3 cm2 V−1 s−1 for DtT, 1.6×10−2 cm2 V−1 s−1 for D3TN, and 3.7×10−2 cm2 V−1 s−1 for DP2TN. The differences in transistor performances were attributed to the degree of π overlap and the morphological differences determined by the molecular structures.