光子晶体滤色实现五基色显示

Application of photonic crystals for colorful display

用反射式光子晶体滤色结构替代传统显示器所用吸收式彩膜,实现红绿蓝黄绿的五基色彩色显示。用时域有限差分法设计和优化光子晶体几何参数,实现特定波长被特定光子晶体结构的光子禁带局域于禁带中被吸收,其他波长透过,只有部分波长的光被反射显色,达到反射式波长选择的目的。结果显示,在玻璃基板上沉积120nm的薄膜硅,通过设计二维圆柱状光子晶体的周期、直径和高度,得到红绿蓝黄青五基色所在的波长范围内的反射出光,且半峰宽都在±50nm左右。反射式光子晶体结构形成的三基色和五基色可以将美国国家电视系统委员会(NTSC)色域分别拓宽到121%和143%,且使色纯度更高。最后,本文提供了一种加工二维柱状结构光子晶体的可行性方案。

A series of photonic crystal structures was proposed to replace traditional absorbing color film, acting as a reflector color filter to realize Red (R), Green (G), Blue (C), Yellow (Y) and Cyan (C). This solution could widen color gamut from 3 primary colors to 5 primary colors, and could improve color purity by reducing the full width at half maxima (FWHM) comparing these traditional absorbing colors. This paper used Finite Different Time Domain methodology to solve Maxwell Function for designing and optimizing different geometrical parameters of photonic crystal structures, to make particular wavelength reflected owing to the photonic band gap. A 120 nm thick layer of silicon was deposited and patterned as two dimensional(2D) pillars, whose pitch, diameter and height are optimized to reflect particular wavelengths for obtaining RGBCY with a ±50 nm FWHM. The RGB and RGBCY five primary colors can extend the color gamma to 121% and 143% of National Television System Committee (NTSC) respectively. Lastly, a fabrication route was introduced to fabricate different kind of photonic crystal structures by using e-beam lithography and etching processes.