A new solar cell obtains a conversion of 47.1%, the highest ever

These new high-performance cells have been published in a laboratory investigation that has been distributed together with a paper in Nature where they detail their operation. Unlike the current panels that use silicon as standard and reach 33% conversion, here new materials, different layers and some other trick are added to increase up to 47.1% efficiency by capturing light and transforming it into electricity.

 How do they do it? 

First, a combination of different light-absorbing materials is used at six junctions (consisting of six different types of layers). Each of them has different materials to collect different parts of the solar spectrum (it is what allows for example to have solar panels that work at night). Thanks to the possibilities of nanotechnology, the solar cell has around 140 layers of these materials in, and here is the magic, a thickness less than that of human hair.

The team of researchers explains that the 47.1% conversion was achieved under a concentrated light of 143 suns. On the other hand, if a light with the concentrated light power of a single sun is used, the conversion efficiency is 39.2%. It is still a very high figure and in fact it is still a record of efficiency for a single sun above them.

Where will we see these solar panels. 

As promising as this new technology for solar panels sounds, it has many difficulties for us to see it worldwide and as a new standard. The reason? The enormous cost of building such solar panels with these highly efficient cells. The team of researchers says they could cut costs by using mirrors to focus light on smaller areas, which would translate into creating fewer solar cells. In other words, use a huge area of mirrors to power a tiny area of ultra-efficient solar cells. This is not something odd, record in solar energy has been pulverized this way.

Where they do seem to have a brighter future is in aerospace technology. The high costs of manufacturing satellites and ships allow investment in technologies such as these new solar cells. In exchange, a greater capture of energy would be obtained in space, where it is probably the most precious asset.

This device really demonstrates the extraordinary potential of multijunction solar cells. 

The paper, "Six-junction III-V solar cells with 47.1% conversion efficiency under 143 suns concentration," appears in the journal Nature Energy. Geisz’s co-authors are NREL scientists Ryan France, Kevin Schulte, Myles Steiner, Andrew Norman, Harvey Guthrey, Matthew Young, Tao Song, and Thomas Moriarty.

To construct the device, NREL researchers relied on III-V materials — so called because of their position on the periodic table that have a wide range of light absorption properties. Each of the cell’s six junctions (the photoactive layers) is specially designed to capture light from a specific part of the solar spectrum. The device contains about 140 total layers of various III-V materials to support the performance of these junctions, and yet is three times narrower than a human hair. Due to their highly efficient nature and the cost associated with making them, III-V solar cells are most often used to power satellites, which prize III-V’s unmatched performance.

Let’s hope that soon we will have these panels available to be used in our homes.