A breakthrough at the labs of researchers at MIT may give a huge boost to photovoltaic panel technology by increasing their efficiency by as much as 25%.
A current theory of the limit to the efficiency of solar cells, known as the Shockley-Queisser efficiency limit, states that for a single optimized semiconductor junction, the conversion efficiency can never go beyond 34%.
But this latest discovery might retire that theory, as the new system is said to be able to double the amount of electrons produced for each photon that hits the cells.
“In a standard photovoltaic (PV) cell, each photon knocks loose exactly one electron inside the PV material. That loose electron then can be harnessed through wires to provide an electrical current.
But in the new technique, each photon can instead knock two electrons loose. This makes the process much more efficient: In a standard cell, any excess energy carried by a photon is wasted as heat, whereas in the new system the extra energy goes into producing two electrons instead of one.” – MIT
The idea behind the new solar cell, “singlet exciton fission”, is based on an older theory that had never been successfully executed, and now the team’s work has shown the first “proof of principle” that it is viable. While this initial system only delivered an energy conversion efficiency of about 2%, the researchers said they could optimize it much further for higher efficiency, which could lead to a boost for organic solar cells of 25% or more.
The results of the team’s work, which was performed in the Center for Excitonics and supported by the U.S. Department of Energy, are published in Science: “External Quantum Efficiency Above 100% in a Singlet-Exciton-Fission–Based Organic Photovoltaic Cell“
If you read this far, we assume you found this post interesting. Please help Blackle Mag thrive by sharing it using the social media buttons below.Tweet
What did you think of this post? Let us know in the comments below.