Study On Structural Color Properties Of Photonic Crystals Composed Of Different Materials

Photonic crystals are artificial micro-nano structures composed of different materials which have two important properties with photonic band gap and photonic localization.The photonic band gap is a wavelength range where the optical waves are prohibited to propagate in the photonic crystal.Therefore,the structural color can be realized by the photonic crystal since the optical waves of different wavebands or wavelengths have different transmittance and reflectance.In recent years,ion beam techniques have been developed rapidly,and they show a trend of interdisciplinary development in physics,chemistry,biology and so on.Ion beam techniques include ion irradiation and ion implantation.In recent years,ion beam techniques have been used to modulate the optical properties of materials.Since the parameters including the refractive index and thickness of the material can be modulated by the ion beam,we investigated theoretically and experimentally the optical properties and structural colors of the photonic crystals by energetic ion beams,where the ion irradiation and ion implantation are considered respectively.In this thesis,the transfer matrix method is used in simulations,and the electron beam evaporation techniques are used to prepare thin films and photonic crystals.The main contents conclude two sections which are as follow.In chapter 2,we studied theoretically and experimentally the effective modulation of the structure colors of all-dielectric photonic crystals by ion irradiation.Firstly,we theoretically designed one-dimensional periodic and defective photonic crystals,respectively.Secondly,two kinds of photonic crystals are prepared by the electron beam evaporation techniques.Moreover,the photonic crystal samples are irradiated by energetic ion beams with different fluences.It is found that the optical spectra of the photonic crystals are blue-shifted with the increase of the fluences of irradiated ions so the structural colors are changed correspondingly.Such results are important for the modulation of structural colors.In chapter 3,we mainly studied theoretically and experimentally the effective modulation of the structural colors of all-dielectric photonic crystals by ion implantation.Firstly,we designed and prepared monolayers and one-dimensional all-dielectric periodic photonic crystals.Secondly,they are implanted by metallic ions with different fluences.It was found that the structural colors of the monolayers presented a mixture of long wavelength and medium wavelength due to the strong absorption in the short wavelength band of the visible spectra after of metal ions are implanted.In addition,due to the strong wideband absorption in the short wavelength and medium wavelength regions of the visible spectra,the structural colors of photonic crystals mainly depend on the mixture of the long wavelength range of the visible spectra.