Development of light emitting devices using artificial photonic synthesis model dendrimers

聚合物激光器件作为下一代通信光纤备受关注。本论文主要研究了光敏化树枝状大分子作为一种新型的聚合物激光介质，通过分子内能量转移测量了发色团(发射中心)激发下的放大自发辐射(ASE)。利用支链单元中的菲与核单元中的茂的直接偶联反应合成了新型光敏树枝状大分子。这些树枝状大分子的荧光测量表明，这些树枝状大分子的荧光基团的激发导致了茂铁核的发射，这表明这是一种有效的能量转移。随着抽运能量的增加(FWHM=47 nm)，含内壳型菲的树枝状大分子的发射带半高宽减小。光谱变窄归因于放大的自发辐射。同时，不含内壳型菲发色团的树枝状大分子(FWHM=84 nm)的发射光谱几乎没有变化。这些结果表明放大的自发辐射受能量转移效率的影响。

Polymer laser devices attracted considerable attention for the next generation optical fiber for communications. In this works, we focused attention on photosensitized dendrimers as a novel polymer laser medium and measured amplified spontaneous emission (ASE) by chromophores (emission center) excitation through intramolecular energy transfer.Novel photosensitized dendrimers were synthesized by combinatorial method employing direct coupling reactions of anthracene of branch units and perylene of a core unit. The fluorescence measurement with these dendrimers revealed that excitation of the anthracene groups led to the perylene core emissions, indicating efficient energy transfer should be involved.Spin-coated polystyrene thin films containing those dendrimers were excited by the third harmonic of pulsed Nd: YAG laser (355 nm). The full width at half maximum of emission band of dendrimers having inner shell anthracene was decreased with increasing pumping energy (FWHM=47 nm). The spectral narrowing were attributed to the amplified spontaneous emission. Meanwhile, the emission spectra were hardly changed in the dendrimers without inner shell anthracene chromophores (FWHM = 84 nm). These results suggested that amplified spontaneous emission is affected by the energy transfer efficiency.