Semitransparent solar cells: a window to the future?
The economics of renewable energy are becoming increasingly favourable. In Australia and many other parts of the world, silicon solar cells already dominate the rooftop market. Rooftop solar power offers an increasingly cheap and efficient way to generate electricity.
But while great for roofs, these silicon modules are opaque and bulky. To design a solar cell suitable for windows, we have to think outside the box.
When we put a solar panel on a roof, we want it to absorb as much sunlight as possible, so that it can generate the maximum amount of power. For a window, there is inevitably a trade-off between absorbing light to turn into electricity, and transmitting light so we can still see through the window.
When thinking about a cell that could be fitted to a window, one of the key parameters is known as the average visible transmittance (AVT). The is the percentage of visible light (as opposed to other wavelengths, like infrared or ultraviolet) hitting the window that travels through it and emerges on the other side.