论文部分内容阅读
用激光荧光法研究了pyrene(芘,嵌二萘)在SiO_2表面上生成excimer(激基缔合物)的机理。在4.2°K温度下,分别用330nm和375nm的激光激发pyrene,可检测到不同的荧光光谱带;在77°K时,分别在392nm和475nm处检测pyrene在SiO_2表面上的激发光谱,也得到不同的激发谱带;说明在实验样品条件下,pyrene在SiO_2表面上有稳定的“静态”eimer存在,当激发这些eimer时,就生成excimer,从而可在475nm附近观察到excimer的特征发射带。然而,不同温度下的荧光光谱又显示出,pyrene吸附在SiO_2表面上除去由dimer受激而直接生成的excimer外,仍有部分“动态”的excimer生成,即由受激的单体pyrene分子在表面通过扩散而和另一个单体pyrene分子形成excimer(就象在溶液中一样)。
The mechanism of the formation of excimer (excimer) on the surface of SiO 2 by pyrene (pyrene) was studied by laser fluorescence spectroscopy. The excitation of pyrene at 330 nm and 375 nm respectively at 4.2 ° K allowed the detection of different fluorescence bands; at 77 ° K, the excitation spectra of pyrene on the surface of SiO 2 were also measured at 392 nm and 475 nm, respectively Different excited bands. It shows that under the experimental conditions, pyrene has a stable “static” eimer on the surface of SiO 2. When these eimer molecules are excited, excimer is generated, and the characteristic emission band of excimer can be observed near 475 nm. However, the fluorescence spectra at different temperatures show that pyrene is adsorbed on the surface of SiO 2 to remove the excimer directly stimulated by dimer. However, there are still some “dynamic” excimer molecules generated by excited monomer pyrene The surface forms an excimer with another monomer, pyrene, by diffusion (as in solution).