Ultrahigh-transparency, ultrahigh-haze nanograss glass with fluid-induced switchable haze

Optoelectronic applications such as solar cells and light-emitting diodes would benefit from glass substrates with both high transparency and high haze to improve power conversion and extraction efficiencies, respectively. In this Letter, we demonstrate glass with grass-like nanostructures that displays ultrahigh transparency and ultrahigh haze (both over 95% at wavelength 550 nm). The nanograss is fabricated by a scalable maskless reactive ion etching process in fused silica where the height is controlled via the etch time. We demonstrate that shorter nanograss ( 6  μm height), though the transmission decreases slightly to less than 92%. Finally, we demonstrate that various fluids with a similar index of refraction as the glass may be used to switch the haze of these substrates.