| Serious environmental pollution and ecological destruction have been caused by the use of the traditional fossil energy such as coal and oil, in addition, the fossil energy is non-renewable and its reserves is diminishing, which makes it difficult to meet human's demand of energy. Therefore, active exploration and development of new energy has its significance. Organic solar cell can convert solar energy directly into electrical energy and it has become a hot research topic in recent years as a low cost?clean utilization of renewable energy, especially, dye-sensitized solar cell is developing rapidly. However, the biggest problem organic solar cell facing is its present energy conversion efficiency can't reach the demand of industrialization. Hence, improving the energy conversion efficiency of organic solar cell from devices and materials has become the main direction of present research. Under this background, we designed and synthesized a series of dye sensitizers based on triarylamine derivative and benzothiadiazole. The structures of the as-synthesized target products were confirmed by 1H-NMR,13C-NMR and MALDI-TOF. The photophysical, electrochemical and photovoltaic properties of the dyes have been investigated by UV-vis spectra, PL spectra and cyclic voltammetry. The main contents are as follows:1. A novel 3D backbone structure triarylamine derivative (IDTTPA) based on triphenylamine were designed and synthesized, and the structure has a unique three-dimensional structure and rich electronic properties. We applied the electron-rich unit to sensitizers as electron donor, inserted benzothiadiazole derivatives as the auxiliary acceptors, benzene as ? bridge and formic acid as the anchoring group, thus two D-A-?-A dye sensitizers (CD1 and CD2) were synthesized and applied to dye-sensitized solar cells (DSSCs). We studied the influence of this triarylamine derivative as electron donor on photovoltaic properties of DSSCs, in the meantime, the influence of the importation of fluorine on auxiliary acceptors also has been studied. The obtained results suggested a high power conversion efficiency could be reached after applying the triarylamine derivative to dye-sensitized solar cells. The introduction of fluorine increased PCE of DSSCs. Under standard global AM 1.5G illumination condition, the PCE values of DSSCs based on CD2 was 7.90% while 6.26% for CD 1, which indicated DFBT is a better choice as auxiliary acceptors.2. Two D-A-?-A organic dyes (HD1, HD2) were designed and synthesized for dye-sensitised solar cells (DSSCs). We studied the influence of changing alkyl group in electron donor and extending ? bridge on photovoltaic properties with the purpose of improving PCE of DSSCs based on this series dyes. Through the system research to physical and optical properties, electrochemical properties and photovoltaic performance of organic dye molecules we found that inserting thiophene although can extend ? bridge but also increase the torsion angles of the electron donor and the ? bridge. The result of interaction between the two is the dye absorption spectrum has a slight blue shift and dye molar extinction coefficient has been decreased, leading to a decline in the efficiency of dye, the efficiency of dye HD1 with thiophene is only 4.01%, current dropped to 8.98 mAcm-2 in HD1 from 12.48 mAcm-2 in CDlwith a 28% decline. After the research to HD2,we found that a longer alkoxy caused a seriously blue shift (70nm relative CD1) in the absorption spectra and the molar absorption coefficient of dye is also low. As a result, the efficiency of the HD2 is only 3.83%, and the current decline 488 mAcm-2, a drop of 39% when compared to CD1. |
PDF Full Text Request