Multilayer broadband antireflective (AR) coatings consisting of porous layers usually suffers poor functional durability. Based on a quarter-half-quarter multilayer structure, AR coatings with dense SiO₂ film as the top layer are designed, and refractive index for each layer is optimized. After heat-treated at only 150 °C, refractive index of Nb₂O₅ film reaches to 2.072 (at 550 nm), which can meet design requirements of the middle layer. TiO₂–SiO₂ composites with controllable refractive indices are selected to be used as the bottom layer. The obtained triple-layer AR coating presents excellent performance, and the average transmittance at 400–800 nm attains 98.41%. Dense layers endow the multilayer structure good abrasion-resistance, and hexamethyldisilazane is further used to modify the surface of the AR coating, which can greatly improve the hydrophobicity of the coating. The proposed triple-layer broadband AR coating has potential value in practical applications of sol–gel deposition.

中文翻译：

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酸催化溶胶-凝胶法低温制备SiO2 / Nb2O5 / TiO2-SiO2宽带增透膜

由多孔层组成的多层宽带抗反射（AR）涂层通常具有较差的功能耐久性。基于四分之一四分之一的多层结构，设计了以致密SiO ₂膜为顶层的增透膜，并优化了每一层的折射率。Nb ₂ O ₅膜仅在150°C进行热处理后，折射率达到2.072（在550 nm），可以满足中间层的设计要求。TiO ₂ –SiO ₂选择折射率可控的复合材料作为底层。所获得的三层增透膜具有优异的性能，在400-800 nm处的平均透射率达到98.41％。致密层赋予多层结构良好的耐磨性，六甲基二硅氮烷还用于修饰AR涂层的表面，可以大大提高涂层的疏水性。提议的三层宽带增透膜在溶胶-凝胶沉积的实际应用中具有潜在价值。