Green Reflector with Predicted Chromatic Coordinates

The color reflector with multiple-layer thin film scheme has attracted much attention because of the potential for massive production by wafer-scale deposition and the possibility to integrate with photonics (semiconductor) devices. Here, an angle-insensitive green reflector with a simple multilayer dielectric thin film structure was reported, with predicted chromatic coordinates based on CIE 1931 standard. The SiN/SiO2 multilayer thin film stack, including a special silicon-rich nitride material with ultrahigh refractive index, was grown alternatively by an inductively coupled plasma chemical vapor deposition (ICPCVD) system at a low stage temperature of 80 degrees C. The green reflector showed a maximum reflectivity of 73% around 561 nm with a full width at half maximum (FWHM) of 87 nm in the visible wavelength range, which contributed significantly to its color appearance. The measurement by an angle-resolved spectrometer under the illumination of p/s-polarized light wave with a variable angle of incidence indicated that the reflectance spectrum blue-shifted slightly with the increasing of incident angle such that the green color could be kept.

Automated summary

This study reports a simple angle-insensitive green reflector with a multilayer dielectric thin film structure, which exhibits predicted chromatic coordinates based on the CIE 1931 standard. The reflector is fabricated by growing a SiN/SiO2 multilayer thin film stack using an inductively coupled plasma chemical vapor deposition system at a low temperature of 80 degrees C. The green reflector achieves a maximum reflectivity of 73% at 561 nm with a FWHM of 87 nm in the visible wavelength range, contributing significantly to its color appearance. Angle-resolved measurements indicate a slight blue shift of the reflectance spectrum with increasing incident angle, allowing the green color to be maintained.