采用离散偶极子近似方法(discrete dipole approximation,简称DDA)从理论上对玻璃基底上不同粒径的Au纳米粒子结构阵列的消光光谱以及消光峰与纳米粒子粒径的关系进行了研究。计算结果显示玻璃基底上的Au纳米粒子结构阵列的消光谱中出现明显区别于Au单体纳米粒子的共振峰,玻璃基底上的Au纳米粒子结构阵列的消光性质与单体纳米粒子的粒径密切相关,随着纳米粒径的增大表面等离子体共振吸收峰出现明显红移,并且在粒径〉40nm时出现多峰吸收现象。计算结果与实验结果基本一致。给出玻璃基底上的Au纳米粒子结构阵列的共振吸收峰随单体纳米粒子粒径变化的关系图。对Au纳米结构阵列的吸收机制进行系统的理论分析。
The method discrete dipole approximation (DDA) was used to theoretically calculate the extinction spectrum of ordered Au nanosphere arrays with different radius on the glass substrate. The DDA simulation of the ultraviolet-visible (UV-Vis) extinction spectra of ordered Au nanosphere arrays with various radius shows different optical properties from isolated Au individuals. The ordered Au nanosphere arrays on the glass sub- strate strongly depend on the radius of Au individuals, that is to say, with the increase of the radius the reso- nance peak was obviously red-shifted and with the radius greater than 40nm there appear to be many resonance peaks not less than two. The calculation result was consistent well with the experiment result. The relationship of the resonance wavelength of ordered array of Au with different radius of single Au sphere was gived. Finally, the resonance regime of ordered Au nanosphere arrays is discussed.