The idea of manufacturing windows that can efficiently collect solar energy is becoming closer to reality due to advances with high technology silicon nanoparticles and research undertaken at the University of Minnesota and the University of Milano-Bicocca.
The research involves embedding silicon nanoparticles into efficient luminescent solar concentrators. The end product allows windows to capture solar energy. The scientific principle is that as light shines through the treated surface of the window, certain frequencies of light become trapped inside. The light is then concentrated towards the edges of the window; here tony solar cells capture the energy and store it.
The windows are termed “photovoltaic windows” and they could become the next big thing in renewable energy technologies. The energy capturing potential is very large, given that most buildings have windows and on large structures like skyscrapers the outer structure is composed mainly of glass.
The idea of using windows to collect energy is not a new one. However, producing windows that are efficient has been difficult. The application of silicon nanoparticles has advanced things considerably. This is important given that silicon is abundant in the environment and non-toxic. In tests silicon has proved efficient in absorbing light at different wavelengths than it emits.
To make the silicon effective, the researchers shrunk the dimension of silicon crystals to a few nanometers (one billionth of a meter). At this tiny size silicon becomes an efficient light emitter. Tests indicate that the silicon nanoparticles can create efficient photovoltaic windows capable of capturing over 5 percent of the sun’s energy.
A further plus point is that the technology cannot be easily seen, so there would be no impact on design or aesthetics. The photovoltaic cells would be hidden within the window frame. The production costs, once the concept becomes commercialized, are also anticipated to be low.
The research has been published in the journal Nature Photonics, with the research paper titled “Highly efficient luminescent solar concentrators based on earth-abundant indirect-bandgap silicon quantum dots.”
