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The intersubband plasmons (ISBPs) of single‐wall carbon nanotubes (SWCNTs) endow SWCNT‐based optoelectronic devices with more functions. However, the structural dependence of the ISBPs of SWCNTs is not fully understood. Here, the effect of electronic types and diameters of SWCNTs on the energy and intensity of their ISBPs is investigated systematically. The results show that the ISBP energy of semiconducting SWCNTs is ≈50–250 meV larger than that of metallic SWCNTs with the same diameters, while the ISBP integral intensity is approximately 1.25 to 4 times stronger. Diameter dependence of ISBPs for both semiconducting and metallic SWCNTs is also observed. With a decrease in diameter, the ISBPs shift to higher energies, while the intensity decreases dramatically. When the diameter is reduced to less than 1 nm, the ISBPs become unobservable. Interestingly, the energy separation between the ISBPs and interband transition S22 (M11) decreases with an increase in diameter. Theoretical calculations show that the structure‐dependent ISBP characteristics are dominated by the electronic states of SWCNTs. Based on the ISBP characteristics of different SWCNTs, high‐performance SWCNT‐based near‐infrared electrochromic devices are fabricated by mixing small‐diameter metallic SWCNTs with semiconducting SWCNTs due to their high conductivity and negligible ISBP signals. [ABSTRACT FROM AUTHOR]

The structure separation of synthetic single-wall carbon nanotube (SWCNT) mixture species with diameters larger than 1.2 nm still remains a challenge. Here, an NaOH-assisted gel chromatography method is used for the structure separation of the SWCNT mixture with a diameter range of 1.2-1.7 nm, in which NaOH is used to tune the interaction between distinct ( n, m) SWCNTs and gel. Incrementally increasing NaOH concentration in SWCNT dispersion selectively enhances the adsorbability of different-structure SWCNTs and enlarges their interaction difference with gel, leading to their structure separation after applying into a gel column system. On this basis, a two-step method is developed for further improving the structure purity of the separated SWCNTs by combining overloading and stepwise elution. These results are well demonstrated by the optical spectra of the separated SWCNTs. This work paves a way for single-chirality separation of large-diameter SWCNTs using gel chromatography technique and is an advanced progress in the structure control of SWCNTs. [ABSTRACT FROM AUTHOR]

Recent development in epidermal and bionic electronics systems has promoted the increasing demand for supercapcacitors with micrometer-thickness and good compatibility. Here, a highly flexible free-standing epidermal supercapacitor (SC-E) with merely 1 μm thickness and high performance is developed. Single-walled carbon nanotube/poly(3,4-ethylenedioxythiophene) hybrid films with unique inner-connected reticulation are adopted as electrodes for ultrathin structure and high electric conductivity. Then, based on two substrates with different surface energies, a stepwise lift-off method is presented to peel off the ultrathin integrated supercapacitor from the substrates nondestructively. As a result of the high conductive hybrid electrodes and the thin electrolyte layer, the as-designed supercapacitors (based on the total mass of two electrodes) achieve a good capacitance of 56 F g−1 and a superhigh power density of 332 kW kg−1, which manifest superior performance in contrast to the other devices fabricated by traditional electrodes. Meanwhile, the ultrashort response time of 11.5 ms enables the epidermal supercapacitor (SC-E) work for high-power units. More importantly, the free-standing structure and outstanding flexibility (105 times bending) endow the SC-E with excellent compatibility to be integrated and work in the next generation of smart and epidermal systems. [ABSTRACT FROM AUTHOR]

Asymmetric supercapacitors with high energy density are fabricated using a self-assembled reduced graphene oxide (RGO)/MnO2 (GrMnO2) composite as a positive electrode and a RGO/MoO3 (GrMoO3) composite as a negative electrode in safe aqueous Na2SO4 electrolyte. The operation voltage is maximized by choosing two metal oxides with the largest work function difference. Because of the synergistic effects of highly conductive graphene and highly pseudocapacitive metal oxides, the hybrid nanostructure electrodes exhibit better charge transport and cycling stability. The operation voltage is expanded to 2.0 V in spite of the use of aqueous electrolyte, revealing a high energy density of 42.6 Wh kg−1 at a power density of 276 W kg−1 and a maximum specific capacitance of 307 F g−1, consequently giving rise to an excellent Ragone plot. In addition, the GrMnO2//GrMoO3 supercapacitor exhibits improved capacitance with cycling up to 1000 cycles, which is explained by the development of micropore structures during the repetition of ion transfer. This strategy for the choice of metal oxides provides a promising route for next-generation supercapacitors with high energy and high power densities. [ABSTRACT FROM AUTHOR]

Conventional methods to produce graphene/silicon Schottky junctions inevitably involve graphene transfer and metal deposition, which leads to the techniques being complicated, high-cost, and environmentally unfriendly. It is possible to directly grow hybrid nanocrystalline graphene/graphite transparent electrodes from photoresist on quartz without any catalyst. Due to the source material being photoresist, nanographene/graphite patterns can easily be made on Si/SiO2 structures to form nanographene/silicon Schottky junctions via commercial photolithography and silicon techniques. The obtained Schottky junctions exhibit excellent properties with respect to photodetection, with photovoltage responsivity of 300 V W-1 at a light power of 0.2 μW and photovoltage response time of less than 0.5 s. The devices also exhibit an excellent reliability with the photovoltage deviating less than 1% when cycled over 200 times. [ABSTRACT FROM AUTHOR]

A high‐performing epidermal supercapacitor is presented W. Y. Zhou, Z. Q. Niu, S. S. Xie, and co‐workers on page 8178. The micrometer‐thin and extremely flexible supercapacitor can reveal the subtle skin texture and manifest a practical potential to power other devices, which is promising for future smart and epidermal systems. [ABSTRACT FROM AUTHOR]