胶体光子晶体环的研制及其光学性能

Fabrication and optical properties of a ring-shaped colloidal photonic crystal

为了满足图案胶体光子晶体在实际应用中的需要,提出旋涂这种简单胶体光子晶体环的快速制备方法。基底为圆型图案光刻胶结构,乳胶球为疏水核亲水壳结构聚(苯乙烯-甲基丙烯酸甲酯-丙烯酸)乳胶球。对所制备的样品进行形貌和光学性能表征,研究了旋涂速度、乳胶球浓度和不同圆型光刻胶图案基底对旋涂过程中乳胶球组装形貌的影响。结果表明制备胶体光子晶体环的最佳参数如下:旋速为2 000 r/min,乳胶球质量百分比浓度为7.5%,圆型光刻胶结构的直径约为22.8μm;环中乳胶球进行相对有序组装,这与光谱图中峰的位置和宽度相一致,分析原因可能是由于组装时间太短导致的。这种快速的胶体光子晶体环的成功构筑归因于图案基底的物理限域和浸润性差异,这种方法可能在光学器件、传感和防伪方面有着广泛的应用前景。

The quick fabrication of ring-shaped colloidal photonic crystal was demonstrated on the circle-pat-terned photoresist substrate by spin-coating,which is promising for practical application.Latex spheres were designed with a hydrophobic core and a hydrophilic shell of poly(styrene-methyl methacrylate-acrylic acid).Scanning Electron Microscopy(SEM)images and reflectance spectra of the as-prepared ring-shaped colloid-al photonic crystals were acquired.The influences of spinning speed,latex sphere concentration and different circle-patterned photoresist substrates on the morphology of the ring-shaped colloidal photonic crystal were investigated.The results indicate that the optimal parameters for preparing a ring-shaped colloidal photonic crystal are achieved with a spinning speed of 2000 r/min,a latex sphere concentration of 7.5%and a circle-patterned photoresist structure(diameter:22.8μm).The SEM images showed that the latex spheres were al-most all deposited at the periphery of the ring and were dispersed with relative order,which was attributed to fast evaporation.This fast self-assembly method for preparing ring-shaped colloidal photonic crystals was achieved by spin-coating and relied on the physical confinement of patterned photoresist substrates and their wettability difference.It will have important applications in optical devices,sensing materials and anti-coun-terfeiting.