Sol–Gel Preparation of Laser Damage Resistant and Moisture-Proof Antireflective Coatings for KDP Crystals

Abstract

Surface fogging induced degradation has been a bottleneck problem in potassium dihydrogen phosphate (KDP) crystals due to they are grown from aqueous solution. In this paper, we developed a facile method to prepare a double-layer antireflective coating with moisture-proof and laser damage resistant properties for KDP crystals. The bottom layer was a poly siloxane coating with dense structure and silanol side groups, while the top layer was a hexamethyl-disilazane (HMDS) modified nanoporous SiO coating. Both of the sols were nonalkaline and nonaqueous to make sure those are harmless to KDP crystals. The double-layer coated KDP crystal exhibited a maximum transmittance of 99.9% with an average increase of transmitted light of 6-7% over the wavelength range between 351 and 1053 nm. After exposure in a 55% relative humidity environment for 6 months, the double-layer HMDS_SiO/PS coating coated KDP crystal displayed nearly the same optical transmittance as the original one, whereas the single-layer HMDS_SiO coated KDP crystal had a transmittance loss of ∼5%. Moreover, the laser-induced damage threshold of the double-layer coating on KDP crystal reached 11.5 J/cm (355 nm, 3 ns). This multifunctional antireflective coating not only can be used for KDP crystals, but also can be applied to thermal-sensitive polymeric substrates.

Bilayer broadband antireflective coating to achieve planar heterojunction perovskite solar cells with 23.9% efficiency

“…According to the theory of ARC on a low-index substrate [32], the refractive index of ARC1 (n 1 ) and ARC2 (n 2 ) should meet n n n n = / , 2 1 air s and the optical thickness of each layer should be around a quarter of the center wavelength (550 nm) of the incident light, i.e., λ/4, to enable a broadband antireflective effect of the bilayer ARC [29,33]. The refractive indices of ARC1 and ARC2 are 1.42 and 1.21, respectively, according to the SE measurements, which satisfy the above equation.…”

Progress on electro-optic crystals for Q-switches

“…熊怀等人 [48] 制 备了SiO2胶体基防潮减反膜, 同时达到防潮和减反射 两个目的, 透过率最高可达到99.7%(波长794 nm), 激 光破坏阈值达16.9 J/cm 2 (波长1053 nm、脉宽1 ns). 王 晓栋等人 [49] 用聚硅氧烷玻璃树脂为原料制备了一种晶 体保护膜, 激光损伤阈值达到28 J/cm 2 (波长1064 nm、 中国科学院福建物质结构研究所对BBO晶体的生 长开展了一系列工作, 1985年生长了φ67 mm×14 mm的 单晶 [51] , 1986年将晶体尺寸扩大到φ76 mm×15 mm [53] , 1988年已经可以生长φ120 mm×23 mm的晶体 [54] .…”

SiO2 Nanoparticles Modified by Bridged Polysilsesquioxane-Based Protective Coatings for Moisture Proofing and Antireflection Applications

“…First the multilayer approach which combines one layer of high refractive index dense material with one or more layers of low refractive index porous materials to form a multilayer composite coating with both moisture barrier and AR performance. 13,14 Xiaodong Wang et al 15 have fabricated a double-layer coating with moisture-proof and AR properties by coating a layer of hexamethyldisilazane (HMDS) modified nanoporous SiO 2 on the surface of a polysiloxane coating with a dense structure and silanol side groups. The coating preparation process is complex, and the adhesive force between two layers is a potential problem which could affect the property and service life of the protective coating.…”

“…Various attempts − have been made to develop a moisture-proof coating with high transmittance, which could be generally categorized into two directions: multilayer and single layer approaches. First the multilayer approach which combines one layer of high refractive index dense material with one or more layers of low refractive index porous materials to form a multilayer composite coating with both moisture barrier and AR performance. , Xiaodong Wang et al have fabricated a double-layer coating with moisture-proof and AR properties by coating a layer of hexamethyldisilazane (HMDS) modified nanoporous SiO 2 on the surface of a polysiloxane coating with a dense structure and silanol side groups. The coating preparation process is complex, and the adhesive force between two layers is a potential problem which could affect the property and service life of the protective coating.…”