| 학회 | 한국고분자학회 |
| 학술대회 | 2004년 가을 (10/08 ~ 10/09, 경북대학교) |
| 권호 | 29권 2호, p.48 |
| 발표분야 | 분자전자 소재의 현황과 전망 |
| 제목 | Room-temperature Nanoscale Ordering of Self-assembled C60-tethered Functional Molecules |
| 초록 | Owing to its unique three-dimensional structure with delocalized π-electrons, C60 and its functional derivatives have been studied extensively due to their very interesting photochemical, photophysical, and electrochemical properties. In particular, C60-based thin films have found a wide range of potential usefulness in photoconductivity, superconductivity upon doping with alkali metals, nonlinear optics, and biological activity. The successful technological application of these thin films relies heavily on novel syntheses to modify C60 with desired functions and the development of methodologies to arrange them on a surface of interest in a highly ordered fashion. Self-assembly technique is a favored approach to achieve thin-film materials because self-assembled monolayers (SAMs) are formed spontaneously by chemisorption, yielding robust and well-defined structures on chosen substrates. Fullerenes covalently bounded to conjugated molecules have been reported to form a long-lived charge-separated state via photoinduced electron transfer. Therefore, various attempts have been made to develop photovoltaic cells with functionalized C60s on electrodes by taking advantage of the structural regularity of SAMs. Recently, Imahori et al. have reported large photocurrent generation in their oligothiophene-linked C60 SAMs on a gold electrode with high quantum efficiency1. More recently, it was discovered in our laboratory that the self-assemblies of 4-mercaptophenyl-9-anthrylacetylene (MPAA) and MPAA-C60 (where C60 is covalently attached at the 10-position of anthracene in MPAA) on Au(111) tend to form a highly ordered two-dimensional staked array through the interplay of strong intermolecular π-π stacking and chemisorptive thiol-gold interactions2,3. In addition, the SAM of MPAA-C60 on gold electrode also demonstrated promising results in efficient photocurrent generation upon illumination with white light. Although both of these results showed very promising photocurrent generation, most C60-molecular dyad or triad systems reported so far have C60s attached linearly to either donor or acceptor segments causing one of the active segments to be embedded when they form a SAM film, which may limit their light harvesting properties (Figure 1a). Our strategy to enhance their light absorption ability is to attach a C60 at both ends of an electron-rich 2,5-dithienylpyrrole chromophore to prevent C60 from blocking the chromophore core so that more light can be absorbed by the chromophore. In this structure, C60s and the chromophore are spatially separated apart which will increase the molecule’s efficiency in light harvesting (Figure 1b). Fig. 1. Schematic representations of SAMs Here we report a newly synthesized rigid C60-tethered 2,5-dithienylpyrrole triad, describing its synthesis, electrochemical properties, and highly efficient photocurrent generation in SAMs. 참고문헌 1. D. Hirayama, K. Takimiya, Y. Aso, T. Otsubo, T. Hasobe, H. Yamada, H. Imahori, S. Fukuzumi, and Y. Sakata, J. Am. Chem. Soc. 125, 532(2004). 2. M. H. Zareie, H. Ma, B. W. Reed, A. K.-Y. Jen, M. Sarikaya, Nano Lett, 3, 139(2003). 3. S. H. Kang, H. Ma, M.-S. Kang, K.-S. Kim, A. K.-Y. Jen, M. H. Zareie, M. Sarikaya, Angew. Chem. Int. Ed., 43, 1512(2004). |
| 저자 | 김경수 |
| 소속 | (주)두산 기술원 |
| 키워드 | Nanoscale ordering; Self-assembly; Photovoltaic; C60 |
