Can you see the invisible glass?

November 20, 2017

What is the scientific achievement?

Self-assembled surface nanotextures reduce light reflections from glass windows to less than 0.2% across the entire visible and near-infrared spectrum, which renders the glass essentially invisible.  Silicon solar cells encapsulated with ‘invisible glass’ outperform conventional devices by eliminating all reflection losses.  These ultra-transparent windows also withstand three times higher optical  power than commercial broadband antireflection coatings.

Why does this achievement matter?

These ultra-transparent windows are useful for enhancing the user experience of consumer devices, improving solar cell performance, and enabling higher-power, pulsed laser applications.

What are the details?

Non reflective glass comparison enlarge

Photograph of a person holding a piece of regular glass (lower), which shows the reflection of an overhead fluorescent light. A similar piece of 'invisible glass' (upper) does not reflect the overhead light and remains completely transparent.

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. Here, we use a highly scalable self-assembly based approach to texture glass surfaces at the nanoscale, reducing reflections by such an extent so as to make the glass essentially invisible. Our nanotextures provide broadband antireflection spanning visible and infrared wavelengths (450–2500 nm) that is effective even at large angles of incidence. This technology can be used to improve the performance of photovoltaic devices by eliminating reflection losses, which can be as much as 8% for glass encapsulated cells. In contrast, solar cells encapsulated with nanotextured glass generate the same photocurrent as when operated without a cover. Ultra-transparent windows having surface nanotextures on both sides can with- stand three times more optical fluence than commercial broadband antireflection coatings, making them useful for pulsed laser applications.

CFN Capabilities:

These ultra-transparent windows are useful for enhancing the user experience of consumer devices, improving solar cell performance, and enabling higher-power, pulsed laser applications.

Publication Reference

A. C. Liapis, A. Rahman, and C. T. Black, Self-assembled nanotextures impart broadband transparency to glass windows and solar cell encapsulants, Applied Physics Letters 111, 183901 (2017).

Self-assembled nanotextures impart broadband transparency to glass windows and solar cell encapsulants (AIP Applied Physics Letters )

Making Glass Invisible: A Nanoscience-Based Disappearing Act (BNL)

Nanotextured glass becomes 'invisible' (C&EN)

Nanoscale textures make glass invisible (UPI)

Nanoscale etching renders glass almost invisible (E&T)

'Invisible glass' could solve smartphone glare problem (The Economic Times)

Scientists may have found a way to make glass virtually invisible (The Irish News)

Spiky cones make glass virtually reflection-free (New Atlas)

Nanometer-tall cones provide antireflective properties, eliminate glare (The American Ceramic Society)

Acknowledgement of Support

This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science User Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704.

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