胶体金纳米颗粒的荧光光谱特性

研究了胶体金纳米颗粒的荧光激发光谱和荧光发射光谱特性.增大激发光的波长,发射峰相应红移并在629nm达到最强,对应的灵敏激发波长为473nm.增加金纳米颗粒粒径,观察到发射谱的峰值先增大然后减小.发射峰产生的原因在于电子与带间空穴的复合导致非线性共振光散射.发射峰强度和金颗粒粒径的关系可以用表面等离子体震荡引起的局域场增强来解释,数值计算结果和实验结果能较好的吻合.

Fluorescence Characteristics of Au Colloidal Nonoparticles

Fluorescence excitation and emission spectrum from Au colloidal nonoparticles was obtained using spectrophotofluorlometer. The emission peak shifts to longer wavelength with the increasing excitation wavelength and reaches the maximum at 629 nm, when the excitation wavelength is fixed in 473nm. With increasing the particle radius, the fluorescence emission peaks increase first and then decrease. This emission is relates to the electron and hole interband recombination. The relationship between particle size and fluorescence intensity have been illuminated from the theory of local field enhancement. The calculation result is in good agreement with the experimental results.