WHY THIS MATTERS IN BRIEF

The use of glass is increasing around the world and scientists are trying to find new ways to enhance its properties.

Recently we saw new research that lets windows turn into mirrors at the flick of a switch, and now researchers from the Institute for Research in Electronics and Applied Physics at the University of Maryland have designed smart windows that can generate solar energy as well as adjust their opacity to either allow or block light at the flick of a  switch. But the solar smart window not only uses the solar power to power itself up but can also store energy for powering other devices – a trick that might not be lost on Lamborghini who recently announced they’re looking for materials that can help them make a battery-less hypercar in 2030.

The teams new technology uses a polymer matrix imbued with microdroplets of liquid crystals and an amorphous silicon layer like those in solar cells. These are then sandwiched in between glass panes.

When turned off, the liquid crystals disperse light, making the window opaque as the silicon absorbs solar energy, which it will later use for powering itself up, or charging other devices connected to it. These liquid crystals adjust when turned on, allowing light to pass through.

The ingenious thing is that even when turned on, the window remains opaque when viewed from certain angles. This means that some light is still absorbed and the window is partially charging while simultaneously allowing light in, maximizing the window’s energy absorption and efficiency.

The ability to switch the windows on and off ensures that users maintain control over the windows not just for temperature management but also for privacy purposes, as opposed to existing solar-powered smart windows which automatically decide when to block out light, and when to allow visibility. This eliminates the need to employ the use of curtains or blinds.

Apart from this, adaptation of its energy efficiency mechanism could revolutionize many optoelectronic devices.

“The ability to electrically control transparency and scattering of light is important for many optoelectronic devices; however, such versatility usually comes with additional unwanted optical absorption and power loss,” said the researchers.

The new solar smart windows also require very little energy for self-powering, as little as 13 nanometers of amorphous silicon. The NASA funded study has been published in ACS Photonics.