| 摘要: | 本論文主要是測量掺雜金屬的階梯型有機共軛高分子(ladder type poly para-phenylene)Ph-LPPP粉末態與薄膜態的樣品在不同壓力下的吸收光譜、螢光光譜、光調制光譜和拉曼光譜等光學特性。在壓力增加的情況下，我們可以看到所有光譜譜線有紅位移和變寬的現象。共軛高分子的pi-pi*電子特性使得分子鍵間距因壓力增加而縮短，導致能隙變小，因而使光譜有紅位移。除此之外，分子的聚集作用造成電子雲層相互干擾，使得分子鏈間的交互作用增強，因此所有的譜線變寬。三重態激子和光漂白的生命期也被描述。由所有的光譜特性可發現壓力會造成分子的平面化，此效應可增加分子間的交互作用，因此增長其有效共軛長度，使得三重態未定域化。透過這份研究，我們可以了解Ph-LPPP的單重態、三重態、震動特性和其有效共軛長度之間的關係。
The optical properties, such as absorption, photoluminescence, photo-modulation and Raman scattering spectra, of blue light-emitting organic conjugated polymer, ladder-type poly(para-phenylene) (Ph-LPPP) with trace-concentration of metallic impurities, both in the powder form and in film form under various pressures were measured. Red-shift and broadening effects were found in all spectra with increasing pressure. Due to the pi-pi* character of conjugated polymers, the distance between bonds decreasing under pressure made the energy gap smaller resulting in the red shifts of spectra. Besides, the aggregates would affect the interfering between electronic clouds, such that the inter-chain coupling was stronger and resulted in the broadening of all spectra of polymer. The lifetimes of the triplet excitions and the photo-bleaching were also reported. The planarization of Ph-LPPP under pressure was discovered through all spectral features, which increases the intermolecular interaction, therefore, the effective conjugated length of the polymer, and causes the delocalization of triplet state. Through this work, we could understand the relationship between the singlet and triplet transitions, as well as the vibronic properties, of Ph-LPPP and its effective conjugated length. |
