Imagine a paint-like sprayable material that could make digital cameras, night vision goggles, and many other electronic devices cheaper and more efficient by using the sun’s energy to create electricity. No, this material is not a new tool for aspiring graffiti artists. It is a paintable plastic, created by a team of U of T scientists led by Steven McDonald, a U of T electrical and computer engineering graduate student. This material is capable of both detecting, and creating electricity from infrared light, which is invisible to our eyes but can be felt as heat. Their study was published in the January 9 issue of Nature Materials.
The team invented a substance that uses tiny particles about one billionth of a meter in diameter. “Through our choice of [the size of the] particles, we were able to select the wavelengths of light which they could absorb,” said Dr. Ted Sargent, the senior author of the study, and Nortel Networks-Canada Research Chair in Emerging Technologies at U of T’s Department of Electrical and Computer Engineering.
This material could potentially improve the performance and cost-efficiency of electronic devices. Digital cameras currently “use silicon to detect light and manage the electronic signals read out by each pixel, said Sargent. “Silicon does not absorb light in the infrared spectral region.”
Furthermore, night vision cameras, which detect heat sources in the dark, “require an expensive infrared-absorbing crystal, which must be connected to the silicon chip,” said Sargent. “Our detector technology could be painted on the silicon chip directly.” This would allow for the manufacture of cheaper night-vision cameras and enhance the performance of digital cameras.
As a result of its ability to convert infrared energy into electricity, this new material could also increase the effectiveness of solar cells. Presently, silicon based solar cells are capable of detecting only a fraction of the total energy emitted by the sun. By also absorbing the invisible energy emitted by the sun, this material could increase the electrical output of solar cells.
Moreover, a “spray-on” plastic would be much cheaper than silicon. However, Sargent hastened to add that this material is not yet ready for consumers. So there’s no need to get too riled up about getting a cheap solar powered home tomorrow, Sargent said that his team was “working hard to make the next breakthrough.”
