A kind of full titanium dioxide one-dimensional photonic crystal and preparation method thereof

Abstract

The invention discloses an all-titanium dioxide one-dimensional photonic crystal and a preparation method thereof. The one-dimensional photonic crystal comprises more than one mesoporous / dense titanium dioxide film pair composed of a mesoporous titanium dioxide film and a dense titanium dioxide film, and the central wavelength of the photonic band gap can be It can be adjusted arbitrarily between 260-800 nanometers, and the reflectivity of the center wavelength of the forbidden band can reach up to 97.3%. The body is obtained by calcining after photocuring, wherein the mesoporous titanium dioxide precursor is composed of a titanium dioxide precursor, polystyrene and a reactive compatibilizer. The invention can easily obtain titanium dioxide thin films with different thicknesses and refractive indices by changing the content, concentration and spin coating speed of polystyrene, so as to regulate the central wavelength of the photonic band gap, and can prepare large-area full titanium dioxide one-dimensional photonic films cheaply and efficiently. crystals.

Description

technical field [0001] The invention belongs to the technical field of film preparation, and in particular relates to an all-titanium dioxide one-dimensional photonic crystal and a preparation method thereof. Background technique [0002] One-dimensional photonic crystal is an important thin film device. For 1D photonic crystals, film quality is critical. The defects of the film during the preparation process seriously affect its optical properties, and the existence of a large number of defects will greatly increase the scattering of light and reduce the adhesion. Sol-gel (Sol-Gel) method, physical vapor deposition (PVD) and chemical vapor deposition (CVD) are the main methods for preparing titanium dioxide thin films at present, but the preparation process of the sol required by the sol-gel method is long, and the film is dry The disadvantages such as easy cracking of the film and poor adhesion to the substrate during calcination are difficult to overcome. The use of PVD...

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Problems solved by technology

The defects of the film during the preparation process seriously affect its optical properties, and the existence of a large number of defects will greatly increase the scattering of light and reduce the adhesion

Sol-gel (Sol-Gel) method, physical vapor deposition (PVD) and chemical vapor deposition (CVD) are the main methods for preparing titanium dioxide thin films at present, but the preparation process of the sol required by the sol-gel method is long, and the film is dry And the disadvantages such as easy cracking of the film and poor adhesion to the substrate during calcination are difficult to overcome. The use of PVD and CVD methods requires expensive instruments, and the preparation efficiency also needs to be improved.

In our previous patent (Document 1 Hu Xin et al., A titanium dioxide / titanium dioxide one-dimensional photonic crystal and its preparation method, ZL 201810190099.4), a method for preparing dense titanium dioxide thin films with high efficiency and large area has been disclosed, but the preparation of large It is still very difficult to control the area of ​​mesoporous titanium dioxide film and its refractive index in a wide range

[0003] The current methods for preparing mesoporous titanium dioxide thin films are basically based on the self-assembly of nanoparticles or self-assembly of templates. The preparation efficiency is low, and the defects cannot be controlled when large-area preparations are made. Most importantly, the refractive index of porous films cannot be adjusted.

Physical deposition methods, such as pulsed laser deposition (document 2L.C.Luca Passoni et al., Self-Assembled Hierarchical Nanostructures for High-Efficiency Porous Photonic Crystals, ACS Nano 2014,8,12167-12174), oblique electron beam evaporation (document 3M.Oliva-Ramirez et al., Optofluidic Modulation of Self-Associated Nanostructural Units FormingPlanar Bragg Microcavities, ACS Nano 2016,10,1256-1264), etc., are also used to prepare mesoporous titanium dioxide films, which require expensive instruments, and Random cracks on the surface of porous films are also unavoidable, forming a large number of defects that cannot be quantitatively characterized

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