金属Al薄膜基微池强制沉积胶体光子晶体的制备

Fabrication of Colloidal Photonic Crystals by a Micro-cell Based on Al Thin Film

强制沉积法是一种利用自组装原理快速沉积胶体晶体有序阵列的模板方法.我们利用微机械刻划法加工金属Al薄膜,Al膜厚控制微粒粒径和聚醚砜膜厚控制层数,成功地制备了用于强制沉积光子晶体的微池装置.为了检验该微池装置的有效性,我们分别测试了不同粒径(224,245和283nm)单分散聚苯乙烯微球的沉积效果,并且对其中一种微球(283nm)进行了不同温度的烘干处理,检验了烘干温度对该样品表面形貌和光子带隙中心波长的影响.实验结果表明,该光子晶体呈面心立方结构,内部晶格完整,缺陷较少,带隙中心波长的实验值与计算值符合得较好.此外,烘干处理可以使构成光子晶体的微球发生微观变化,并导致光子带隙中心波长的蓝移.

Colloidal photonic crystals were synthesized by a forced deposition method. A new micro-cell was developed through thermal deposition and micro-mechanical score, by replacing conventional photosensitive resin with Al thin film and polyether-sulfone membrane. The Al film thickness could control the sphere size, and the polyether-sulfone membrane thickness could control the layers of colloidal photonic crystals. Monodispersed colloidal polystyrene spheres with different sizes were used to deposit the colloidal photonic crystals in the micro-cell to confirm the validity of this method. SEM patterns and transmission spectra show that the crystals exhibit a face-centered cubic structure with low defect density, and the band gap agrees with the calculated result very well. Furthermore, a drying process could influence the shape of the polystyrene spheres, resulting in a blue shift of the photonic band gap.