as a result 4 the rising annealing temperature induces si02 phase to form, also ivolves the formation of a si phase . in high-temperature-annealed sio ~, films the excess silicon atoms are present as si-si4 tetrahedra, randomly dispersed in the amorphous si02 matrix . photoluminescent spectra were observed for the samples excided by the laser whose wavelength is 365nm . the pl peak is located at about 445nm, which dose n't shift as the annealing temperature changes . as the annealing temperature is raised, the luminescent intensity increases . the phenomena suggest that the si-o-si bond as a defect center which is broken down by the stress at the si nc / si02 interface is the primary source of blue luminescence 这个陡的界面由于明显的晶格结构的差别而有较大的应力。界面的形成伴随着界面发光中心的增加,同时pl强度在l户800有一个大的增强。这个结果提示我们,界面上h0s工键断裂形成的nbohc应是蓝光发射的主要原因。
the composite films assembled from [ a-siw12o40 ] 4-and dye molecules showed characteristic luminescence of the dyes and the emission intensity increased almost linearly with the number of bilayers . moreover, extremely high luminescent intensity of the composite films can be obtained by using dye solutions with very low concentrations keggin型多金属氧酸盐-染料复合膜均显示出染料分子的特征发光,发射峰强度随双层数增加而几乎线性增长,而且从极低浓度的染料溶液制备的超薄复合膜即可达到极高的发光强度。