周期性银纳米颗粒阵列的光学特性

Optical Properties of Periodic Silver Nanoparticle Arrays

利用剪裁的纳米球掩模沉积技术制备了周期性的银纳米颗粒与银纳米孔阵,并探讨了相关纳米结构的光学特性。先在玻璃基片上制备六角密排的聚苯乙烯纳米球作为掩模,然后利用电子束蒸镀银金属,在超声中去掉掩模,最终可以获得周期性的银纳米三角颗粒。若在蒸镀银金属前先对聚苯乙烯纳米球进行氧等离子体刻蚀,可以获得周期性的银纳米孔阵。测量上述银纳米颗粒与银纳米孔阵中纳米银的透射谱,对其表面等离子体共振特性进行了分析。同时,利用三维时域有限差分方法对相关纳米结构的光吸收特性进行了数值模拟,理论模拟与实验结果基本相符。

Periodic silver nanoparticles and nanohole arrays were prepared through tailored nanosphere lithography, and the optical properties of the fabricated nanostructures were investigated. First, a hexagonal close-packed monolayer comprising polystyrene (PS) nanospheres was made on a glass substrates as a mask. Then, the silver film was deposited in the voids between the nanospheres using an electron beam evaporator. After deposition, the PS nanospheres were removed, affording an array of silver nanoparticles. If the PS nanospheres were tailored through reactive-ion etching prior to the silver deposition step, the nanoparticles merged with the adjacent particles and produced periodic silver nanohole arrays. A series of nanostructures were prepared, and their surface plasmon resonance characteristics were analyzed by measuring the transmission spectra. The optical properties of the related nanostructures were numerically simulated using the finite difference time domain, the results of which were consistent with those of the experiments.