5 Ws of Invisible Glass

Who

Users of consumer electronics devices and solar cells, and high-power pulsed laser applications.

What

Most optoelectronic components and consumer display devices require glass or plastic covers for protection against the environment. Optical reflections from these encapsulation layers can degrade the device performance or lessen the user experience. A highly scalable, self-assembly-based approach to texture glass surfaces at the nanoscale reduces reflections by such an extent that the glass is essentially invisible. The technique can be used to nanotexture almost any material, with precise control over the size and shape of the nanostructures. It eliminates reflections from glass windows not by coating the glass with layers of different materials, but by changing the geometry of the surface at the nanoscale.

Glass surfaces with etched nanotextures reflect so little light that they become essentially invisible. This effect is seen in this image, which compares the glare from a conventional piece of glass (right) to that from nanotextured glass (left), which shows no glare at all.

This cross-sectional image from a scanning electron microscope shows a glass surface textured with 170-nanometer-tall cones. The cones are packed very close to each other (52 nanometers apart). A 2” piece of glass has 900 billion cones on its surface.

Where

Center for Functional Nanomaterials (CFN), Brookhaven National Laboratory, Upton, NY

When

The technique has been demonstrated and tested, and the CFN is seeking partners to help advance the materials toward commercialization.

Why

If you’ve ever watched television in anything but total darkness, used a computer while sitting underneath overhead lighting or near a window, or taken a photo outside on a sunny day with your smartphone, the major nuisance of modern display screens was evident — glare. It could also be a promising alternative to the damage-prone antireflective coatings conventionally used in lasers that emit powerful pulses of light, such as those applied to the manufacture of medical devices and aerospace components.