基于金属-介质薄膜的反射型彩色滤光片

Reflective Color Filters Based on Metal-Dielectric Thin Films

基于诱导反射原理设计了一种可见光波段金属-介质薄膜结构的反射型彩色滤光片。高吸收铬和高反射铝的应用使它既能获得高反射率又有很高的宽波段截止度,通过改变介质匹配层的厚度实现适当的导纳匹配,得到了反射率大于72%、较高色饱和度的红绿蓝三色滤光片。实验制作了样品,测试结果与设计相吻合。基于半色调技术,采用光刻和剥离工艺制备了不同面积占空比的滤光片阵列,实现了高分辨率、介于红绿蓝三色之间中间色的光学反射单元。

Reflective color filters with metal-dielectric thin films in visible range are designed based on induced reflection method. High-absorption chromium and high-reflection aluminum enable these color filters to acquire both high reflectance and cut-off level in a broadband spectral region. Red, green and blue reflective filters with the reflectance larger than 72% and wide color gamut are obtained by adjusting thickness of their matching dielectric layers respectively for proper admittance matching. Filter samples are experimentally fabricated and the measured results agree well with those of the simulation. According to the halftone technique, filter arrays with different area duty ratios are prepared by lithography and stripping technology to realize optical reflective units with high resolution and intermediate colors among red, green and blue.