Abstract
AbstractThis dissertation is aimed to synthesize arylene ethynylenes compounds that emit fluorescence with high quantum yield. We hope that we can synthesize a new material, which emit blue fluorescence, for constructing Light Emitting Diode (LED).We used some theoretical calculation to assist the design for a potential blue emitting material, which we need. We used Heck reaction to synthesize a monomer, and then the monomer is polymerized with the use of different polymerization methods: (1) Using V, VI group transition metal chlorides such as NbCl5 as a catalyst for polymerization. (2) Synthesizing arylene ethynylenes compounds by spacer linker.Besides, some basic physical characteristics of arylene ethynylenes compounds are also discussed. They are lifetime of the compound, thermal behavior, electrochemical behavior and finally the device characteristic behavior using the basic data’s such as UV-Visible spectrum and fluorescence spectrum.We found that the characteristics of UV-Visible spectrum and fluorescence spectrum depend on the solvent and concentration of the electroluminescence material. In higher concentrations the characteristics of fluorescence spectrum is highly affected, possibly due to the formation of excimer resulting from aggregation of fluorescence molecules at higher concentrations.We measured the quantum yield for the series of arylene ethylenes compounds using Coumarin 102 as standard, and the results show that the new blue-light emitting material that emits fluorescence with high quantum yield.The lifetime of the material is not affected in dilute concentrations. But it is affected in the higher concentrations because of the formation of the excimer and aggregation phenomenon. The lifetime becomes shorter when the dipole-dipole interaction between fluorescence compound and solvent interaction become stronger.From the electrochemical behavior of the electroluminescence material it is concluded that the compounds are suitable for the electroluminescence layer and/or electron transfer layer. The thermal behavior study shows that the material is thermally stable (up to a temperature of ca. 300 ℃). By the use of the prepared electroluminescence material we have done the light emitting device and some research on the characteristic of the device.