Flexible and mechanically stable antireflective coatings from nanoporous organically modified silica colloids

Abstract

We report the preparation of flexible and mechanically stable antireflective organically modified silica (ormosil) coatings at ambient conditions. Thin films are obtained from colloidal suspensions of ormosil gels which are prepared using methyltrimethoxysilane (MTMS) and tetraethyl orthosilicate (TEOS) monomers. The ormosil suspensions are directly applicable and suitable for the large-area deposition of nanoporous ormosil thin films. The nanoporosity of the films can be tuned by changing the monomer ratio of the starting solution. Thin films on flexible substrates retain their antireflective properties even after 100 cycles of excessive bending without a significant change in transmission. Furthermore, the films remained intact after water dripping and adhesive tape tests. In addition, thin films on glass substrates are found to exhibit antifogging properties after annealing at 600 °C for 30 min. The ease of fabrication and multifunctionality of these films make them ideal coatings for flexible electronic and optoelectronic devices, sensors, and solar cells. © 2012 The Royal Society of Chemistry

Superhydrophobic and Omnidirectional Antireflective Surfaces from Nanostructured Ormosil Colloids

“…47,48 The phase separation in the gels can be decreased by using some additional tetra-functional monomers such as TMOS and TEOS. 28,49 Accordingly, ormosil colloids with smaller grains can be obtained from these less phase separated gels.…”

“…These results revealed that the grain size distribution of ormosil colloids highly depended on the amount of MTMS monomer used in gel synthesis. 28 It is well-known that trifunctional MTMS monomer (i.e., it contains three hydrolyzable methoxy and one nonhydrolyzable methyl ligands) induces phase separation in gels due to low solubility of cyclic and cage-like structures formed during polymerization. 47,48 The phase separation in the gels can be decreased by using some additional tetra-functional monomers such as TMOS and TEOS.…”

A colloidoscope of colloid-based porous materials and their uses

“…Very small colloids (<30 nm), such as organically modified silica (ORMOSIL) particles, can be used to generate uniform antireflective coatings, but typically require the addition of stabilizing elements to make robust films. [198][199][200] Larger colloids can be used, with or without other materials, to generate hierarchically structured materials with very high transmission values. 188,201,202 Figure 9 shows an example of such a structure created by using a monolayer of colloids as an etch mask to make a grating structure on which a disordered array of gold nanoparticles is created.…”

Soft biomimetic tapered nanostructures for large-area antireflective surfaces and SERS sensing

“…[12][13][14][15] However, they are inefficient in terms of angle-dependence and are feasible only for narrowband applications. Therefore, anti-reective structures (ARSs) are essential for optical devices, solar cells, light emitting diodes (LEDs), and displays in order to prevent undesired reection.…”