European scientists come up with a way to enhance perovskite based solar cells, better preparing them for commercialization. It involves the application of a new molecule that can assemble itself in to a monolayer upon contact with the panels surface.
In a collaboration between chemists from Kaunas University of Technology (KTU), Lithuania and physicists from Helmholtz Zentrum Berlin (HZB) science institute, Germany a new molecular solution has been composed for better application over-top of perovskite based solar cells.
Perovskite solar panels provide great promise for surpassing current limits to conversion efficiency holding back their silicon counterparts. That is – the amount of light that is actually converted in to electricity. Back in October scientists solved a problem involving thermal instability in perovskite solar panels, now they are working out how to construct compatible selective contacts
Along with a new chemical composition comes a complete overhaul in what elements will do for selective contact. In solar power, contacts are part of the cell that either disperses extra electrons to avoid overload or acts as a conductive filament for whatever charge transfer is required to generate use-able energy.
So the international team created what they call “molecule V1036”, a liquid that adheres to the surface, arranging itself in to a single layer one molecule thick. In this case self assembled monolayers (SAM) are usually associated with control over wetting and adhesion, chemical resistance, bio compatibility, sensitization, and molecular recognition for sensors and nano fabrication. However, they found that by dipping certain components of the solar panel in to a gat of molecule V1036 they could improve selective contact and therefor conversion efficiency.
Furthermore, chemists claim that this SAM can evenly cover any oxide surface including those found in silicon architecture. This versatile approach will likely give it an edge over other nanomaterials in the solar industry.
“It’s not polymer, but smaller molecules, and the monolayer formed from them is very thin. This, and the fact that the monolayer is being formed through dipping the surface into the solution makes this method much cheaper than the existing alternatives. Also, the synthesis of our compound is a much shorter process than that of the polymer usually used in production of perovskite solar cells,” says Ernestas Kasparavičius, Ph.D. student at KTU Faculty of Chemical Technology.
“In our laboratory in Kaunas we studied use of the self-organising molecules to form the electrode layer as thin as 1-2 nm, evenly covering all the surface. During my internship in Berlin I was able to apply our material and to produce a first functioning solar element with just a monolayer-thick selective contact,” says Magomedov, a researcher at KTU Faculty of Chemical Technology.
They add that Molecule V1036 requires very low material consumption for comparably high conversion efficiency. In this case – 18 percent, which is remarkable for a new technology. It usually takes subsequent stages of refinement to achieve that same level of efficiency.