Synthesis And Investigation Of Novel Indoline Sensitizers For Dye-sensitized Solar Cells

With the rapid development of the global socio-economic, energy and environmentalproblems facing humanity gradually increased in the21st century. With the non-renewablefossil fuels, especially coal and oil, over-consumption of resources could trigger a new roundof human energy crisis. In order to find a renewable energy instead of fossil fuels, researchersled research in the field of new energy boom. Among the many energy sources, solar energyas a renewable energy is the most promising energy sources. Compared with fossil fuels, solarenergy has many advantages: a rich deposit of total reserves; environmentally friendly energy;without geographical restrictions; a convenient development and utilization and so on. Inshort, with the excessive consumption of non-renewable resources, to find a renewableresources is a necessary work.Solar cells are one of the most direct means of converting solar energy into electricalenergy, which is all along an important research focus in this field. The dye-sensitized solarcells (DSSCs) as a new solar cell have further developed, because it has a high photoelectricconversion efficiency, a low manufacturing cost, a simple preparation process and so on. Dyesensitizer is a key component which is the most concern by researchers in dye-sensitized solarcells. In recent years, organic dye sensitizer which has many advantages: a high photoelectricconversion efficiency, a simple preparation process, a low production costs and easy tuning,etc., is highly concerned about the vast number of researchers, meanwhile organic dyesensitizers have also been rapid development.Considering this, in this context we designed and synthesized two organic dyes, andstudied their performance as a solar cell sensitizer.Chapter1The fabrication, mechanism and performance characterization of thedye-sensitized nanocrystalline solar cells were briefly introduced in this chapter, in which thedevelopment of the sensitizers were reviewed in detail. At last, the idea and research plan inthis thesis were proposed.Chapter2Two different units (thiophene and furan) with different degree in electrontransporting ability were introduced into the indoline unit instead vinyl thiophene asconjugated π-bridge, carbazole-indoline linking group as a dye electron donor (donor), acyano acrylic acid as an electron acceptor (acceptor), designed and synthesized two newdonor-donor-π-acceptor (D-D-π-A) system of sensitizing dyes WBS-1T and WBS-1F.Chapter3Using C-CA as the reference dye, detailed investigation of photochemical and electrochemical properties of the two dyes were carried out. Meanwhile three dyes were alsosimulated at their optimized geometry by hybrid density functional theory (B3LYP) with the6-31G*basis set as implemented in the Gaussian03program to understand the electronicproperties.Chapter4Photovoltaic property of DSSCs sensitized by WBS-1T and WBS-1F werestudied in detail while the C-CA was used as the reference dye. WBS-1F showed the bestperformance with a Jscof16.28mA cm-2, a Vocof779mV, an FF of0.748, and a η=9.49%.In addition, three dyes were applied in the ionic liquid electrolyte DSSCs. With excellentstability, WBS-1F also showed the highest η value of8.03%. After1000h aging test, theintegrated photoelectric conversion efficiency η remains7.60%, only5%lower than theinitial value.Chapter5Conclusions.