Longqiang Ye

Mechanically stable single-layer mesoporous silica antireflective coating on solar glass

A single-layer antireflective (SLAR) coating with extremely high photovoltaic transmittance (TPV) at 400–1100 nm was designed with the aid of thin film design software (TFCalc™). The AR coating was prepared by evaporation-induced self-assembly using tetraethylorthosilicate (TEOS) as precursor and cetyltrimethylammonium bromide (CTAB) as template. The measured PV transmittance reaches as high as 98.7%, which is in good agreement with the theoretical value. Meanwhile this SLAR coating has excellent mechanical robustness, which passed the 3H pencil hardness test and abrasion test. This SLAR coating with high transmittance and good mechanical properties will find important application in the field of solar cells.

Non-supercritical drying sol–gel preparation of superhydrophobic aerogel ORMOSIL thin films with controlled refractive index

Superhydrophobic aerogel ORMOSIL (organically modified silicate) thin films with controlled refractive index were prepared by a one-pot sol–gel process without supercritical drying. The method involved the preparation of ORMOSIL particles by co-condensation of tetramethylorthosilicate (TEOS) and dimethyldiethoxysilane (DDS) and a further surface modification of ORMOSIL particles with hexamethylsilazane. The particle growth process of ORMOSIL sols and the drying process of aerogel ORMOSIL thin film are discussed in detail. The co-condensation of TEOS and DDS and the surface modification significantly improved the hydrophobicity and hence the environmental resistance of the thin films; the water contact angles of the thin films increased from 23° to 151°. A superhydrophobic aerogel ORMOSIL thin film with refractive index as low as 1.10 was obtained. In addition, the refractive indices can be tailored in the range of 1.10–1.23.Graphical AbstractSuperhydrophobic aerogel ORMOSIL (organically modified silicate) thin films with controlled refractive index were prepared by sol–gel process without supercritical drying.

Environment-resistant fluoro-containing antireflective coatings for high-powered laser systems

A simple sol–gel route was proposed to prepare environment-resistant fluoro-containing antireflective (AR) coatings with nearly 100% transmittance by co-condensation of tetraethylorthosilicate and 1H,1H,2H,2H-perfluoroalkyltriethoxysilanes (POTS). These AR coatings can find great applications in high-powered laser systems.

Preparation of porous silica films in a binary template system for double-layer broadband antireflective coatings

Porous silica films with a refractive index varying from 1.44 to 1.15 were prepared and applied to realize a double-layer broadband AR coating. The porous silica films were obtained using tetraethylorthosilicate (TEOS) as precursor and a binary template as porogen which was composed of cetyltrimethylammonium bromide (CTAB) and polypropylene glycol (PPG). The molar ratio of the two templates was optimized, and a hypothetical mechanism for the cooperative assembly of silicates with the binary template system was proposed. The two layers had the same skeleton despite different porosity with the top layer much more porous than the bottom one. The double-layer double-wavelength AR coating had excellent optical properties with transmittances of 99.6% and 99.8% at 532 nm and 1064 nm, respectively.