| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 가을 (10/13 ~ 10/14, 제주 ICC) |
| 권호 | 30권 2호 |
| 발표분야 | 탄소나노튜브 및 고분자 복합재료 |
| 제목 | Electrical and Field-Emission Properties of Chemically Assembled Single-Walled Carbon Nanotube Patterns |
| 초록 | Because of their low-threshold field for emission and high emission current, carbon nanotubes (CNTs) have attracted much attention as electron field emission materials. Practical applications require that a high density of CNTs can be patterned at selective positions with excellent durability and large-scale control of location and orientation. A high-density structure of patterned CNTs has superior emission characteristics, and stable adhesion between the patterned CNTs emitter and the substrate is important for the stability of such devices. Therefore, for the practical use of CNTs in field emitter applications, a high-resolution patterning method producing high-density structures with strong adhesion is required. Previous methods for assembling and integrating single-walled carbon nanotubes (SWNTs) on device surfaces include direct growth by chemical vapor deposition (CVD)1, self-assembling techniques2, and screen-printing from a paste mixture of CNTs. However, these methods have some limitations in large-scale applications because of the high temperatures required, low resolution, low surface density, and inefficient processing. Here, we report a novel fabrication method for patterning of SWNTs with high-density and excellent surface adhesion by the covalent attachment of carboxylated SWNTs (ca-SWNTs) onto an amine pre-patterned glass with the aid of a condensation agent. We also report the electrical properties and field emission characteristics of these SWNT patterned arrays. A high-density SWNT pattern was fabricated with a photolithographic and chemical assembly process. In order to form the SWNT pattern, the substrate was treated with acid-labile group protected amine, and an amine pre-pattern was formed using a photolithographic process with a novel polymeric photo acid generator (PAG). The polymeric PAG contains a triphenylsulfonium salt on its backbone, and was synthesized to obtain a PAG with enhanced efficiency and ease of spin-coating onto the amine-modified glass substrate. The SWNT monolayer pattern was then formed through the amidation reaction between the carboxylic acid groups of carboxylated SWNTs (ca-SWNTs) and the pre-patterned amino groups. High-density multilayer was fabricated via further repeated reaction between the carboxylic acid groups of the ca-SWNTs and the amino groups of the linker with the aid of a condensation agent. The formation of covalent amide bonding was confirmed by X-ray photoelectron spectroscopy analysis. SEM and UV-vis-NIR results show that the patterned SWNT films have uniform coverage with high surface density. The resolution of the SWNT pattern described in this paper is very high compared to those of patterns obtained with conventional methods.3 Further, the high-density structure of the ca-SWNT film has good electrical conductivity and electron emission properties, and the strong adhesion of the patterned SWNT layer should improve the reliability of devices using such films. The electrical resistivities of the SWNT layers were found to be 5 ~10 W cm, with a turn-on electric field of about 3 V/mm at an emission current density of 10 mA/cm2.4 This novel method using a continuous photolithographic process and simultaneous chemical deposition can easily be applied to mass production over large areas of a large number of substrates. Thus this process can be used in the fabrication of the emission cathodes of field-emission displays. It is also potentially applicable to highly integrated devices such as solar cells, batteries, flat panel displays, sensors, and semiconductor devices, because this method can be used with various substrates at mild temperatures. References 1. SohnJ. I. , S. H. Lee, Y. H. Song, S. Y. Choi, K. I. Cho, and K. S. Nam, Appl. Phys. Lett. 78, 901 (2001). 2. S. J. Oh, Y. Cheng, J. Zhang, H. Shimoda, and O. Zhou, Appl. Phys. Lett. 82, 2521 (2003). 3. M. S. Jung, S. O. Jung, D. H. Jung, Y. K. Ko, Y. W. Jin, J. M. Kim,and H. T. Jung, J. Phys. Chem. B 109, 10584 (2005). 4. M. S. Jung, Y. K. Ko, D. H. Jung, D. H. Choi, H. T. Jung, J. N. Heo, B. H. Sohn, Y. W. Jin, and J. M. Kim, Appl. Phys Lett. 87, 013114 (2005). |
| 저자 | 정명섭1, 정성욱2, 허정나2, 이정희2, 김종민2, 정희태3 |
| 소속 | 1삼성종합기술원 / 한국과학기술원, 2삼성종합기술원, 3한국과학기술원 |
| 키워드 | carbon nanotubes; photolithography; field emission |
