In this study, two kinds of homopolymers (PPDOT, and P3HT), and three different proportions of copolymers (PPDOT-co-P3HT=1:1, PPDOT-co-P3HT=3:1, and PPDOT-co-P3HT=1:3) have been synthesized successfully by Grignard metathesis.
PDOT and 3HT, which are both of monomers, are electron-donating. Due to the fact that PDOT was caused larger than 3HT by pushing effect, it can change the conjugation length to be much longer, resulting in lower energy level of HOMO, and thus reduce energy gap of high molecular. These polymers possess optical bandgaps in the range of 1.908 to 1.922 eV. The desirable absorption attributes of these materials make them to be the excellent candidates for use in organic solar cells.
In this study, the analysis and discussion of these polymers were measured by TGA, DSC, XRD, GPC, NMR, UV, PL, and AC-2 for thermal stability, crystallinity, structure and optical properties. From the XRD, materials of main chain ordered are well crystalline, which can increase the absorption of thiophene ring. By UV, we could find absorption region of infrared light increase that is beneficial to enhance ISC, but led to lower HOMO, and thus reduced VOC. However, the overall device power conversion efficiencies indicate that increasing ISC is much greater than decreasing VOC. Hence, power conversion efficiency increased. However, in PL, intensity of the emission is large, and it will cause components to quenching that lead to reduce its efficiency.
We knew HOMO-LUMO energy level matching relations of polymer materials which were mixed with PCBM as the active layer of organic solar cells by UV-VIS and AC-2. From the instructions of device power conversion efficiency, because efficiency is not high, it causes the short circuit. The reason is (1) energy level can not match (2) the solubility of PPDOT is not very good, hence the film is not easy even. The way to improve is to identify a better solvent to increase its solubility.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0901110-112322 |
| Date | 01 September 2010 |
| Creators | Wu, Chien-Chih |
| Contributors | Tzong-Liu Wang, Wen-Yao Huang, Yu-Kai Han, Shiao-Wei Kuo, Ko-shan Ho |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0901110-112322 |
| Rights | not_available, Copyright information available at source archive |
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