Increased Photovoltaic Efficiency

Newly published findings point to increased possible production efficiency in solar cells.  Historically, affordable photovoltaic cells have been subject to the “Shockley Queisser limit”.  Queisser’s limit concludes that single junction cells are only capable of achieving a maximum of 29% to 33% efficiency in photovoltaic production.  Marc Baldo, Electrical Engineering and Computer Science professor at MIT, has found a possible method of surpassing that limit.

Photovoltaic Production

Solar cells generate electricity by using sun generated photons to pass through electron laden silicon cells and pull them into a circuit.  Traditional solar cells use silicon which provides infrared photons.  The infrared photons carry less energy than photons within the visible part of the magnetic spectrum.  Currently each infrared photon pulls a single electron into the circuit.  However, that equation is doubled using a molecular organic semiconductor called “tetracene”.

Tetracene Solutions & Problems

Tetracene splits blue-green photons into two separate energy packets.  The two packets are each capable of pulling an electron.  Thus, the amount of electrons carried by a single photon is doubled.  Seemingly, tetracene is a practical solution for increased photovoltaic production efficiency.

There are challenges with implementing tetracene into silicon cells.  If applied directly to silicon, tetracene the electrical charge is destroyed.  A layer of hafnium oxynitride is a plausible solution to seperate the two materials in a solar cell. 

Future of Solar Panel Design

Currently tetracene applications to photovoltaic is in experimental phase.  The concept is concrete, but tetracene inclusion in photovoltaic cells is a long way off.  The solar industry remains hopeful with regard to Marc Baldo’s work at MIT.

Royal Society of Chemistry

Energy Storage on the Horizon
Community Solar Power Summit 2019