다공성 양극 알루미늄 산화물 template를 이용한 공액 고분자 nanorod의 제조 및 특성 = Preparation and characterization of conjugated polymer nanorod arrays using anodic aluminum oxide templates

다국어 초록 (Multilingual Abstract)

Highly ordered anodic aluminum oxide (AAO) was used as templates for fabrication of conjugated polymer nanorod arrays. Nanorod arrays consist of regio-regular poly(3-hexylthiophene) (RR-P3HT) or its mixture with [6,6]-phenyl C61-butyric acid methyl ester (PCBM) (RR-P3HT:PCBM). The AAO templates were prepared by a two step anodizing process in oxalic acid electrolyte. The templates had a highly ordered structure with uniform cell lengths of ~100К？-3,930 nm and pore diameters of ~25-80 nm. Conjugated polymer nanorod arrays were prepared by filling of polymer solutions into the pores of AAO templates using two different methods: infiltration by vacuum (Method V) and infiltration by spin-coating (Method S). Firstly, RR-P3HT nanorod arrays into AAO templates were prepared on an indium tin oxide (ITO) electrode by capillary force in a vacuum oven after drop-coating of RR-P3HT solutions on ITO glass. Due to an appropriate temperature and capillary force in the vacuum oven, the drop-coated RR-P3HT solution was infiltrated into the AAO templates. After removal of the templates, the well-aligned RR-P3HT nanorod arrays were formed with diameters of ~55 nm and heights of ~70 nm. Furthermore, large-area, non-collapsed, and vertically aligned conjugated polymer nanorod arrays on supporting layer were obtained by Method S. In this method, drop-coated RR-P3HT polymer solution was infiltrated into the AAO templates during the spin-coating. The optical absorption spectra of the conjugated polymer films and nanorod arrays prepared with heat treatment are studied. The absorption coefficient over wavelength of 520 nm, particularly on the red shoulder at 600 nm, increases for nanorod arrays. This indicates that the degree of the RR-P3HT chain packing increases in nanorod arrays resulting a higher crystallinity than spin coated film. Significantly, these methods offer a potential technique platform for high-performance nanorod-based polymer solar cell devices and might enable one bottom-up strategy for future nanotechnologies.

목차 (Table of Contents)

• ChapterⅠ. Introduction = 1
• 1-1. Nanostructures = 1
• 1-2. Anodic aluminum oxide (AAO) = 3
• 1-3. Fabrication of polymer nanostructures by AAO templates = 4
• 1-4. Applications for solar cells of polymer nanorod arrays by AAO templates = 5
• ChapterⅡ. Experimental = 7
• 2-1. Materials = 7
• 2-2. Fabrication of highly ordered AAO templates = 8
• 2-2-1. Electro-polishing process = 10
• 2-2-2. 1^(st) anodizing process = 10
• 2-2-3. Etching process = 10
• 2-2-4. 2^(nd) anodizing process = 11
• 2-2-5. Pore-widening process = 11
• 2-3. Fabrication of conjugated polymer nanorod arrays by AAO templates = 12
• 2-3-1. Infiltration of conjugated polymer into AAO templates = 12
• 2-3-1-1. Infiltration by vacuum (Method V) = 12
• 2-3-1-2. Infiltration by spin-coating (Method S) = 14
• 2-3-2. Etching of AAO templates = 16
• 2-4. Characterizations = 18
• Chapter Ⅲ. Results and Discussion = 19
• 3-1. Fabrication of highly ordered AAO templates = 19
• 3-2. Fabrication of highly ordered conjugated polymer nanorod arrays = 23
• 3-2-1. Infiltration of RR-P3HT into AAO templates by vacuum (Method V) = 23
• 3-2-1-1. Effects of RR-P3HT solvents = 23
• 3-2-1-2. Effects of RR-P3HT concentrations = 26
• 3-2-1-3. Effects of cell lengths = 28
• 3-2-1-4. Effects of pore diameters = 30
• 3-2-2. Formation of RR-P3HT nanorod arrays with etching = 32
• 3-2-3. Formation of RR-P3HT:PCBM nanorod arrays = 34
• 3-2-4. Infiltration of RR-P3HT into AAO templates by spin coating (Method S) = 36
• 3-2-4-1. Formation of RR-P3HT nanorods in AAO template by spin coating = 36
• 3-2-5. Formation of RR-P3HT nanorod arrays with etching = 40
• 3-2-6. Optical property of conjugated polymer nanorod arrays = 42
• Chapter Ⅳ. Conclusions = 46
• Chapter Ⅴ. References = 48
• Acknowledgement = 54