One-Step Etching Characteristics of ITO/Ag/ITO Multilayered Electrode in High-Density and High-Electron-Temperature Plasma.

This paper presents the dry etching characteristics of indium tin oxide (ITO)/Ag/ITO multilayered thin film, used as a pixel electrode in a high-resolution active-matrix organic light-emitting diode (AMOLED) device. Dry etching was performed using a combination of H2 and HCl gases in a reactive ion etching system with a remote electron cyclotron resonance (ECR) plasma source, in order to achieve high electron temperature. The effect of the gas ratio (H2/HCl) was closely observed, in order to achieve an optimal etch profile and an effective etch process, while other parameters-such as the radio frequency (RF) power, ECR power, chamber pressure, and temperature-were fixed. The optimized process, with an appropriate gas ratio, constitutes a one-step serial dry etch solution for ITO and Ag multilayered thin films.

Designing Neat and Composite Carbon Nanotube Materials by Porosimetric Characterization.

We propose a porosimetry-based method to characterize pores formed by carbon nanotubes (CNTs) in the CNT agglomerates for designing neat CNT-based materials and composites. CNT agglomerates contain pores between individual CNTs and/or CNT bundles (micropore < 2 nm, mesopores 2-50 nm, and macropores > 50 nm). We investigated these pores structured by CNTs with different diameters and number of walls, clarifying the broader size distribution and the larger volume with increased diameters and number of walls. Further, we demonstrated that CNT agglomerate structures with different bulk density were distinguished depending on the pore sizes. Our method also revealed that CNT dispersibility in solvent correlated with the pore sizes of CNT agglomerates. By making use of these knowledge on tailorable pores for CNT agglomerates, we successfully found the correlation between electrical conductivity for CNT rubber composites and pore sizes of CNT agglomerates. Therefore, our method can distinguish diverse CNT agglomerate structures and guide pore sizes of CNT agglomerates to give high electrical conductivity of CNT rubber composites.

Controlling exfoliation in order to minimize damage during dispersion of long SWCNTs for advanced composites.

We propose an approach to disperse long single-wall carbon nanotubes (SWCNTs) in a manner that is most suitable for the fabrication of high-performance composites. We compare three general classes of dispersion mechanisms, which encompass 11 different dispersion methods, and we have dispersed long SWCNTs, short multi-wall carbon nanotubes, and short SWCNTs in order to understand the most appropriate dispersion methods for the different types of CNTs. From this study, we have found that the turbulent flow methods, as represented by the Nanomizer and high-pressure jet mill methods, produced unique and superior dispersibility of long SWCNTs, which was advantageous for the fabrication of highly conductive composites. The results were interpreted to imply that the biaxial shearing force caused an exfoliation effect to disperse the long SWCNTs homogeneously while suppressing damage. A conceptual model was developed to explain this dispersion mechanism, which is important for future work on advanced CNT composites.