Design and Preparation of a Functional One-Dimensional Photonic Crystal with Low Emissivity in the Region of 8-14 μm

Low-emissivity materials are widely used in thermal radiation control. They can be made of photonic crystal (PC) characterized by the band gap where the emissivity is low. By introducing a defect (doping), a high emissivity peak can be achieved at a certain wavelength in the band gap to make the PC more composite and multifunctional. In this paper, three commonly-used coating materials, namely, Ge, ZnSe, and Si, are adopted to produce a PC which is poorly emissive in 8-14 mu m and highly emissive at 10.6 mu m due to a Si doping layer. With such a special spectrum, this kind of PC has the potential of suppressing detection by both far-infrared and CO2 laser radiation. The spectrum of the sample obtained by Fourier transform infrared spectrometer is in satisfactory agreement with the theoretical curve.