Soon we will see windows, that could change their tint or opacity, to keep out unwanted heat or light. A team from Princeton has developed a self-powered smart window system that uses a transparent solar cell to harvest UV energy from sunlight. Smart windows are made of electrochromic materials that allow them to change their tint from clear to dark blue in response to small electric currents. This current comes from solar cells made of contorted hexabenzocoronene (cHBC) derivatives, which can absorb a specific range of wavelengths. The whole system can be incorporated into a thin, transparent film that can be fitted over panes of ordinary glass. These solar cells can be transparent and occupy the same footprint of the window without competing for the same spectral range. This is a smart management of the entire spectrum of sunlight.
When dark, the system can block out up to 80 percent of visible light. In the future the team wants to develop a smart film that can be applied to existing windows, allowing to change the tint from a smartphone. The app would help to control the sunlight passing into you home, improving energy efficiency, comfort and privacy.
The paper was published in the journal Nature Energy and demonstration of the technology can be seen in a video below.
Source: Princeton University