The future of solar power got a little brighter recently thanks to some new research concerning colloidal quantum dots. These nanoparticles can show great promise in the field of photovoltaics because of how cheaply they can be produced. Typically that cheapness comes at the cost of efficiency, but researchers at the University of Toronto have found a way to address that without necessarily increasing costs too much.
Quantum dots are nanostructures of a semiconductor that has been carefully grown to have specific properties, such as what frequency light they react to. Often these frequencies are above that of infrared light, which comprises the bulk of what hits Earth from the Sun, so a large amount of power is being lost. Work has been done to make the dots effective in the infrared part of the spectrum, but this usually involves adding metal nanostructures that will also absorb light but will not convert it to electricity, causing electricity to still be lost. What the Toronto researchers have done is found a way to use gold nanoshells, which are an example of a plasmonic material, to affect the quantum dots and make them sensitive to infrared light, increasing their efficiency by thirty-five percent to 11% overall.
Currently this research is a proof of concept because while the gold works, it would not be ideal for mass production. Instead the researchers are going to try to find another, cheaper material that replicates the plasmonic effects of the gold.
Source: University of Toronto