Seung Bo Yang

Recent advances in hybrids of carbon nanotube network films and nanomaterials for their potential applications as transparent conducting films

The use of carbon nanotubes (CNTs) as transparent conducting films is one of the most promising aspects of CNT-based applications due to their high electrical conductivity, transparency, and flexibility. However, despite many efforts in this field, the conductivity of carbon nanotube network films at high transmittance is still not sufficient to replace the present electrodes, indium tin oxide (ITO), due to the contact resistances and semi-conducting nanotubes of the nanotube network films. Many studies have attempted to overcome such problems by the chemical doping and hybridization of conducting guest components by various methods, including acid treatment, deposition of metal nanoparticles, and the creation of a composite of conducting polymers. This review focuses on recent advances in surface-modified carbon nanotube networks for transparent conducting film applications. Fabrication methods will be described, and the stability of carbon nanotube network films prepared by various methods will be demonstrated.

Patterned nano-sized gold dots within FET channel: from fabrication to alignment of single walled carbon nanotube networks†

We have introduced patterned gold dots between the electrodes of single walled carbon nanotube (SWNT) network films, to effectively guide the path of randomly assembled nanotube networks. Direct visualization results show well-aligned SWNT networks across the gold dots, generating improved SWNT–FET performance with a high on/off ratio of 104 and 85 cm2 V−1s−1 mobility, a remarkable enhancement compared to SWNT–FET in the absence of patterned gold dots. Unlike previously reported alignment techniques used, the proposed method affords the selective alignment of SWNTs within electrodes at room temperature without any direct growth on the device surface, and without the need for further alignment procedures. Thus, this gold-dot pattern technique within FET channel has proven to be truly simple, reliable and cost-effective. We discuss the effect of the voltage, channel size and feature dimensions of the gold nanopatterns in field effect transistor (FET) structures.

Tin nanoparticle thin film electrodes fabricated by the vacuum filtration method for enhanced battery performance

A novel method for fabricating tin nanoparticle thin film electrodes that show good performance in lithium ion batteries during cycling is reported. The vacuum filtration method has the advantage of affording a high degree of dispersion of the electrode components, thereby providing good electrical contacts between the tin nanoparticles and the conductive carbon or current collector. The reversible capacity and initial Coulombic efficiency are 726 mA h g(-1) and 85.3%, respectively, with this thin film electrode. Cycle life performance tests under real battery conditions show that the battery capacity and reaction peaks remained stable for up to 50 cycles. SEM shows that the uniform morphology of the vacuum filtered film was maintained throughout the cycle life test. This novel vacuum filtration method for providing nanoparticle-based film electrodes has further potential applications for use in various devices such as high power, thin film batteries, supercapacitors and organic-inorganic hybrid photovoltaic cells.