High Transparency, High Haze Nanostructured Glass with Fluid-Induced Switchable Haze

Glass substrates are a critical component of a variety of optoelectronic devices, such as lighting, solar cells, smartphones, and light-emitting diodes (LEDs). Glass with both high haze and high transparency can greatly improve extraction deficiencies and power conversion in these devices. Currently, the most common approach to creating glass with these characteristics is to increase light scattering through the use of texturing, i.e., sand blasting, power blasting, and acid-etching. However, these methods face many technological and economic barriers to widespread adoption and have generally been unable to achieve both haze and transparency above 90% at the optimal wavelength. Our invention is comprised of a simple mask-less, one-step fabrication method for the formation of sub-wavelength nanostructured glass that achieves above 95% for both haze and transparency and could improve the rate of production of optical devices at a large scale, all without increasing the cost.

Cross-section SEM images of nanostructured glass with a grass-like texture.

Description

The glass used in optoelectronic devices must function to protect them from the ambient environment while allowing light to pass through and interact with the underlying photoactive layers of the device. Increased haze and transparency of the glass substrates affects how much light scatters into or out of the photoactive layers and can result in improved efficiency. However, current methods used to accomplish this increased light scattering via texturing generally create substrates that are relatively limited in their haze and transparency. Furthermore, the textured glass made contains large surface features that make them impossible to be integrated into optoelectronic devices without added processing steps, thereby increasing the cost of production. Conversely, our nanostructured glass is fabricated through a scalable mask-less one-step reactive ion etching (RIE) process on fused silica glass. It offers high haze and high transparency simultaneously created via a single process, making it an ideal glass substrate to be used in optoelectronic devices.

Applications

· Solar cells
· Smartphones
· Tablets
· Backlit liquid crystal displays (LCDs)
· LEDs
· Smart glass
· Wearable tech

Advantages

· Achieve both high haze factor and high transparency in glass
· Switchable haze from the addition and removal of water
· One-step fabrication method
· Low cost of production

Invention Readiness

Prototype

IP Status

https://patents.google.com/patent/WO2018222661A1