| Summary: | 碩士 === 國立中山大學 === 光電工程學系研究所 === 104 === In this research, a series of poly(arylene ether)s polymer are synthized and applied in blue organic light-emitting diodes . We use organic light-emitting diodes in host and guest doping system, the choice of the host material is Spirobifluorene of difluoro and glycol derivatives and guest material is Anthracene of difluoro derivatives.
Because of the large steric hindrance and the more rigid structure, spirobifluorene derivatives have high thermal stability and film morphological stability. Many papers use these materials as host materials or coupled with spirobifluorene to improve thermal stability and film morphological stability. Anthracene derivatives has special emitting and electrochemical properties, and it’s easy to change the structure of the materials. So
Anthracene derivatives are common blue materials, but it has some problems on thermal
stability and easy to crystallize when it is in solid state, these limit it applications on
organic light-emitting diodes. Due to the PL spectra of Spirobifluorene’s and the great overlap of Anthracene’s absorption spectra, host materials can use Förster energy transfer to transfer the energy to the guest materials.Therefore, they have good luminous efficiency. We use condensation polymerization to synthesize polymer, and this way can remains the light-emitting characteristics, color purity, and efficiency of a small molecule material, while improving the thermal stability of the polymer and has easy processing properties.
We use different ratios of the Anthracene derivatives and Spirobifluorene derivatives to synthesize a series of blue polymers.The polymer P50 with a doping ratio of 50% shows a pyrolysis temperature of up to 609℃. And the other polymers show the pyrolysis temperature up to about 638 ℃. On solid state, polymer P2.5 with a doping ratio of 2.5% has the relative strongest PL spectra, but there is a little energy transfer which is not completed close to 380nm. By comparison, the energy transfer of polymer P5 with a doping ratio of 5% is almost completed, 5P and 2.5P are almost luminous intensity. Therefore, the doping concentration of 5% would be better on solid state.
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