Conductivity dopants are used in organic light-emitting devices (OLEDs) to reduce the operating voltage and consequently improve the power efficiency. Here, we report the synthesis, as well as photophysical and electroluminescent properties, of an organic molecular p-type conductivity dopant: 1,3,4,5,7,8-hexafluorotetracyanonaphthoquinodimethane (F6-TNAP). F6-TNAP was obtained in a three-step two-pot synthesis from commercially available octafluoronaphthalene. When 1%-5% of F6-TNAP was coevaporated with N,N 0 -di-1-naphthyl-N,N 0 -diphenyl-1,1 0 -biphenyl-4,4 0 diamine (R-NPD) an absorption band at 950 nm was formed, which is attributed to charge transfer and assigned to the F6-TNAP radical anion. Single-carrier (hole-only) devices fabricated with F6-TNAP doped into R-NPD as the hole transport layer (HTL) show a >2 V decrease in operating voltage, compared to the undoped device. A decrease in operating voltage was also demonstrated in blue OLED devices using a F6-TNAP-doped HTL, with only a slight decrease in external quantum efficiency, thus resulting in a net improvement in power efficiency. These results demonstrate that F6-TNAP may be useful in generating high-efficiency OLEDs.

Lithium-sulfur (Li-S) batteries are regarded as one of the most promising candidates for next generation energy storage. To realize their practical application, however, a high S active material loading is essential. The binder material used for the cathode is therefore crucial as this is a key determinant of the bonding interactions between the active material (S) and electronic conducting support (C), as well as the maintenance of intimate contact between the electrode materials and current collector.Here, we investigated the application of polyamidoamine (PAMAM) dendrimers as functional binders in Li-S batteries. Utilizing the high degree of surface functionalities, interior porosities, and polarity of the PAMAM dendrimers, it is demonstrated that high S loadings (>4 mg cm -2 ) can be easily achieved using simple processing methods. An exceptional electrochemical cycling performance was obtained as compared to cathodes with conventional linear polymeric binders such as carboxymethyl cellulose (CMC) and styrenebutadiene rubber (SBR), which was attributed to better interfacial interactions between the dendrimers and the C/S composite materials, as well as better electrolyte wetting due to the dendrimer spherical molecular, porous architectures. Furthermore, the dendrimer-based Graphical AbstractThe critical nanoscale design parameters of dendrimers are exploited as functional watersoluble binders for high sulfur loading lithium-sulfur batteries. The high functional group density, high curvature and porosity, polarity, and ample nitrogen and oxygen functional groups in the dendrimers enabled strong dendrimer interactions with the carbon-sulfur composites, and superior cyclability compared to linear water-soluble binders such as CMC-SBR.

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Developing hierarchical porous carbon (HPC) materials with competing textural characteristics such as surface area and pore volume in one material is difficult to accomplish, particularly for an atomically ordered graphitic carbon. Herein we describe a synthesis strategy to engineer tunable HPC materials across micro-, meso-, and macroporous length scales, allowing the fabrication of a graphitic HPC material (HPC-G) with both very high surface area (>2500 m/g) and pore volume (>11 cm/g), the combination of which has not been attained previously. The mesopore volume alone for these materials is up to 7.53 cm/g, the highest ever reported, higher than even any porous carbon's total pore volume, which for our HPC-G material was >11 cm/g. This HPC-G material was explored for use both as a supercapacitor electrode and for oil adsorption, two applications that require either high surface area or large pore volume, textural properties that are typically exclusive to one another. We accomplished these high textural characteristics by employing ice templating not only as a route for macroporous formation but as a synergistic vehicle that enabled the significant loading of the mesoporous hard template. This design scheme for HPC-G materials can be utilized in broad applications, including electrochemical systems such as batteries and supercapacitors, sorbents, and catalyst supports, particularly supports where a high degree of thermal stability is required.