New PV-Solar Materials
Dutch language video
Physicist Dave Blank of the TU-Twente in the Netherlands explains why the photo-voltaic effect isn’t necessarily confined to semi-conductors like silicon.
Classic solar cells require a metal mesh to conduct the electrons that are split of from the crystal due to the impact of light. Metal however is not transparent for light, reducing the electron yield. What you really want is materials that are both transparent and conductive.
Blank draws a comparison between an Indonesian treat with a Dutch name, the spekkoek, a left over the colonial era. The cake is layered and consists of ingredients you wouldn’t want to eat separately, but in combination are delicious:
Blank uses the spekkoek as a model for new materials to be applied in photovoltaic technology, where the desired photovoltaic effect results from combining (ultra-thin) layers of a few atoms thick. These layers are produced using a laser, ejecting atoms from a source medium, that are deposited on a substrate. By shooting electrons from the side it is possible to accurately control the thickness of each atom layer.
To make a long story short, by combining layers, one can obtain physical properties that the individual layers do not possess, like conductivity at the interface of two non-conductors, that are additionally both transparent. All of a sudden, plastics for instance could become materials useful in electronics and solar technology. Think windows as solar panels, windows in homes, cars and busses.
[source] In the works: a transparent smartphone, enabled by plastics that receive properties, useful in electronics.
By piling layer upon layer, each with different properties, it is possible to absorb a far greater part of the entire radiation spectrum.
To be continued.
[utwente.nl] – 580.000 euro voor onderzoek aan alternatieve zonnecellen
[utwente.nl] – Dave Blank “mr. Nano” retires as professor UTwente
[nanonextnl.nl] – Core Dutch nano-technology program
[wikipedia.org] – Spekkoek