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New Material for More Efficient Solar Cells
PunkerTFC writes "Space.com has an article on a new material that could create relatively cheap solar cells which are up to 50% efficient. This is much better than the 25% efficient silicon solar cells (most common) or the 36% efficient multi-junction solar cells (very expensive). The material was created by "forcing oxygen into a zinc-manganese-tellurium crystal" creating more band gaps, which allow the cell to create electrical energy with three seperate frequencies of light. This could lead to cheap, high-output solar cells in the future, but it will take at least 3 years to assess the feasibility of the new technology, according to the researchers."
It exists already.
This has been released very recently - it's based on PbSe crystals instead - at Los Alamos but also through University of California.
This was already covered by /. a few weeks ago, but this new space.com article does seems tohave more details.
Tellurium is about $14/lb. Gallium, by comparison, is about $1000/lb, which is why gallium-arsenide photocells, which can reach 30% efficiency, aren't widely used.
World production of tellurium is only about 100 metric tons. Gold production is 25 times larger. Tellurium is cheap because it is produced as a byproduct of copper smelting. Nobody mines tellurium directly at present. So there may be a supply problem if demand increases substantially.
You could always electrolyze water and store the hydrogen and oxygen in tanks. The tanks of gas become your battery and a power cell can be used to generate electricity on demand.
I am not denying that this is possible, but it has to be acknowledged that now the main cost driver of your system is probably not in the solar cells but in this oxygen/ hydrogen separation, storage and electricity generation system. Which illustrates my main point which is that good solar cells are not by themselves sufficient to enable this form of a solution (although of course they are a great step).
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