Abstract:
Here, we introduce polymer of intrinsic microporosity 1 (PIM-1) to design single-layer and multilayered all-inorganic antireflective coatings (ARCs) with excellent mechanical properties. Using PIM-1 as a template in sequential infiltration synthesis (SIS), we can fabricate highly uniform, mechanically stable conformal coatings of AlOx with porosities of ∼50% and a refractive index of 1.41 compared to 1.76 for nonporous AlOx that is perfectly suited for substrates commonly used in high-end optical systems or touch screens (e.g., sapphire, conductive glass, bendable glass, etc.). We show that such films can be used as a single-layer ARC capable of reduction of the Fresnel reflections of sapphire to as low as 0.1% at 500 nm being deposited only on one side of the substrate. We also demonstrate that deposition of the second layer with higher porosity using block copolymers enables the design of graded-index double-layered coatings. AlOx structures with just two layers and a total thickness of less than 200 nm are capable of reduction of Fresnel reflections under normal illumination to below 0.5% in a broad spectral range with 0.1% reflection at 700 nm. Additionally, and most importantly, we show that highly porous single-layer and graded-index double-layered ARCs are characterized by high hardness and scratch resistivity. The hardness and the maximum reached load were 7.5 GPa and 13 mN with a scratch depth of about 130 nm, respectively, that is very promising for the structures consisting of two porous AlOx layers with 50% and 85% porosities, correspondingly. Such mechanical properties of coatings can also allow their application as protective layers for other optical coatings.
摘要:
这里,我们引入固有微孔聚合物1(PIM-1)来设计具有优异机械性能的单层和多层全无机减反射涂层(ARC)。使用PIM-1作为顺序渗透合成(SIS)的模板,我们可以制造高度均匀的,机械稳定的共形AlOx涂层,孔隙率为50%,折射率为1.41,而无孔AlOx为1.76,非常适合高端光学系统或触摸屏中常用的基材(例如,蓝宝石,导电玻璃,可弯曲玻璃,等。).我们表明,这样的薄膜可以用作单层ARC,能够将蓝宝石的菲涅耳反射在500nm下仅沉积在衬底的一侧,降低至0.1%。我们还证明了使用嵌段共聚物沉积具有较高孔隙率的第二层能够设计渐变折射率双层涂层。仅具有两层且总厚度小于200nm的AlOx结构能够将正常照明下的菲涅耳反射在宽光谱范围内降低至低于0.5%,在700nm处具有0.1%反射。此外,最重要的是,我们表明,高度多孔的单层和梯度指数双层ARCs的特点是高硬度和耐划痕性。硬度和最大达到的负载为7.5GPa和13mN,划痕深度约为130nm,分别,这对于由两个具有50%和85%孔隙率的多孔AlOx层组成的结构非常有希望,相应地。涂层的这种机械性能还可以允许它们作为其它光学涂层的保护层应用。