Study On Antireflection Coatings Prepared By Hollow Silica Nanoparticles

In this research, the single-layer, double-layer, and three-layer antireflection coatings were prepared by hollow silica nanoparticles, the reflectivity of the glass substrate surface was reduced effectively, and the main research contents is as follows:Using tetraethyl orthosilicate (TEOS) as the raw material and polyacrylic acid (PAA) as the nucleating material, hollow silica nanoparticles were synthesized on the basis of the traditional method of Stober, the preparation of hollow silica nanoparticles with ammonia as the initiator, the size and void fraction of the hollow silica nanoparticles were controlled precisely by changing the amount of PAA and TEOS, the core-shell structure of the hollow silica nanoparticles were observed by the transmission electron microscopy (TEM), and the average particle size of the hollow silica nanoparticles was measured by laser particle analyzerThe hollow silica nanoparticles with suitable particle size and viod fraction were chosen on the basis of the antireflection coating system design theories of single-layer, double-layer, and three-layer antireflection coatings. And the single-layer, double-layer, and three-layer antireflection coatings were prepared by self-assembly. The effect of deposition cycle, pH value of the hollow silica nanoparticle dispersion, particle size and viod fraction of the hollow silica nanoparticles on the transmittance of the coatings were investigated. The deposition cycles are reduced from10cycles to2cycles by acid pickling which simplifies the coating process. The transmittance of single-layer antireflection coatings was measured by using a ultraviolet-visible spectrophotometer in the range of350-800nm, the transmittance of double-layer antireflection coatings was measured by using a ultraviolet-visible-near infrared spectrophotometer in the range of350-1500nm as while as the transmittance of three-layer antireflection coatings in the range of350-2000nm. The surface morphology of the antireflection coatings were observed by the scanning electron microscopy (SEM), and the refractive index and thickness of the antireflection coatings were measured by the ellipsometer. The results show that under optimum conditions, the transmittance of glass substrate coated by the single-layer antireflection coatings increases significantly in the range of350-800nm and the maximum transmittance can be improved from91.6%to98.1%at the optimized wavelength (λ=520nm), the transmittance of glass substrate increases more than5%in the range of400-800nm, the transmittance of glass substrate coated by the double-layer antireflection coatings increases more than5%in a wide wavelength range which is from400nm to1500nm, while the transmittance of glass substrate coated by the three-layer antireflection coatings increases more than5%in a much wider wavelength range which is from400nm to2000nm.