Carbon Nanotube (CNT) Honeycomb Cell Area-Dependent Optical Reflectance

Fabrication of Self-Assembling Carbon Nanotube Forest Fishnet Metamaterials

The investigation of the preparation of polystyrene (PS) nanosphere monolayers for the fabrication of carbon nanotube (CNT) forest fishnet metamaterial structures is studied in this paper, as a cheap alternative for top-down patterning methods. The precise control of dry etching conditions resulted in a highly controlled diameter of PS nanobeads, which were then used as a shadow mask for CNT fishnet preparation. The change of the size of the holes from 370 nm to 665 nm resulted in a gradual change of the CNT morphology from multi-walled to single-walled CNTs. The ultraviolet-visible (UV-Vis) reflectance spectra showed that the variation of the hole diameter resulted in the nonlinear light absorption in CNT fishnets that caused the change of the resonance frequency. The change of the fishnet wire width (inductance) and the hole size (capacitance) resulted in the blueshift of the broadband resonance frequency peak. The presented work has a significant potential to allow for the large-scale fabrication of CNT-based fishnet metamaterial structures for applications in energy harvesting, energy storage, solar cells, or optoelectronic devices, such as neuromorphic networks.

Highly Efficient and Stable Organic Solar Cells via Interface Engineering with a Nanostructured ITR-GO/PFN Bilayer Cathode Interlayer

An innovative bilayer cathode interlayer (CIL) with a nanostructure consisting of in situ thermal reduced graphene oxide (ITR-GO) and poly[(9,9-bis(3'-(N,N-dimethylamion)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl) fluorene] (PFN) has been fabricated for inverted organic solar cells (OSCs). An approach to prepare a CIL of high electronic quality by using ITR-GO as a template to modulate the morphology of the interface between the active layer and electrode and to further reduce the work function of the electrode has also been realized. This bilayer ITR-GO/PFN CIL is processed by a spray-coating method with facile in situ thermal reduction. Meanwhile, the CIL shows a good charge transport efficiency and less charge recombination, which leads to a significant enhancement of the power conversion efficiency from 6.47% to 8.34% for Poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl} (PTB7):[6,6]-phenyl-C71-butyric acid methyl ester (PC71BM)-based OSCs. In addition, the long-term stability of the OSC is improved by using the ITR-GO/PFN CIL when compared with the pristine device. These results indicate that the bilayer ITR-GO/PFN CIL is a promising way to realize high-efficiency and stable OSCs by using water-soluble conjugated polymer electrolytes such as PFN.