Synthesis And Properties Of Coumarin Dyes For Dye-sensitized Solar Cells

21st century, energy issue has become one of the most important problems facing humandevelopment. Today, the world’s energy consumption mostly comes from coal, oil, natural gasand other fossil energy. These non-renewable energy and the use of energy brought about bythe problem of environmental pollution make human research and develope renewable energyincluding bio-energy, wind, hydro, nuclear and solar. It is also to solve the worldwide energycrisis and environmental problems in several important ways. In a variety of energy sources,solar energy has unparalleled advantages：compared with fossil fuels, solar energy is relativelyinexhaustible; compared with nuclear energy, solar energy is more secure, and the applicationwill not cause any pollution to the environment; compared with hydro and wind solar energy,utilization is lower cost and without geographical restrictions. The use of solar energy is solarenergy into electricity.The dye-sensitized solar cells as a new family of solar cells has the advantage of a higherphotoelectric conversion efficiency, low cost, simple fabrication process. Dye as the key inthe dye-sensitized solar cells, has aroused the concern of worldwide research team. The paperwere designed and synthesized two series of pure organic sensitized dye, and study theirperformance as a solar cell sensitizer.In chapter one, briefly introduced the structure and working principle of thedye-sensitized nanocrystalline solar cells, nanocrystalline semiconductor electrode, thesensitizer and electrolyte, and reviewed research progress on efficient organic solar cellsensitizer in recent years. Based on, proposed design thinking and research in this thesis.In chapter two, designed and synthesized one serie of new2D-Ï€-A system dye: MS-C,MS-F and MS-M. The coumarin dyes respectively used carbazole, fluorene and methyl as asecond electron-donating group, forming to two electron donor structure （2D）, usingcyano-acetic acid as electron-withdrawing groups（acceptor） and thiophene unit as a bridgechain,In chapter three, carried out a detailed study to photochemical, electrochemical andoptical and electrical properties of the three dyes. MS-C finging carbazole unit is mostconducive to absorb more sunlight by comparative study on the nature of the spectrum. MS-Chas the most negative LUMO level, which means that the chance of the excited electrons ofinjecting into the TiO₂conduction band and the electron injection efficiency are maximum.Therefore, based on these two aspects to consider, the MS-C is more suitable as ahigh-efficiency dye-sensitized, especially suitable for applications that require thin TiO₂film’s quasi-solid and solid-state dye-sensitized solar cells. Testd recombination lifetime of theelectronic through the I-V, IPCE, and studied the photovoltaic performance of thecyano-acetic acid photosensitive dye.In chapter four, synthesized C-2, F-2and M-2used rhodanine-3-acetic acid forelectron-based, and studied these photophysical and electrochemical properties;In chapter five, conclusions.