Josh-D. S. Davis

Xaminmo / Omnimax / Max Omni / Mad Scientist / Midnight Shadow / Radiation Master

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Photovoltaics
Josh 2004 Happy
joshdavis
Waiting for photovoltaic cells that use a phosphor coating to translate photons into energy levels that can be more readily absorbed. I'd made a note to look into this, and when I did, it looks like there were some promising results about 5 years ago with UV to visible translation, and a factor of 14 improvement in electric output. But, that's just for the UV component. Maybe some sort of prism could be used to split visible light off to one PV cell, and UV to another, while IR could go to either another, or maybe used for a thermocouple of sorts. Something this big would really only be efficient if you could use multiple reflectors to focus more light onto the PV cells. Hrmmm.
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(Deleted comment)
It IS technobabble!

BUT, Phosphor is a phosphorous containing chemical. There are bunches of them. They receive light or electrons at one energy/color and emit light at a different color.

This is how TVs used to work, but there are some that take in UV, which isn't really absorbed by PV cells, and then emits light in a color that IS absorbed by PV cells.

Thermocouples use 2 different kinds of metal, and where they are melted together, it forms a junction sort of like semiconductors. One metal will be more positive, and one will be more negative. Electrons normally wiggle around, and do it more when they are hot (heat is just wiggling faster).

The 2 metals basically form a funnel for the electrons, and so they literally flow (faster = higher voltage) based on the temperature difference between the hot side (pushing electrons out) and the cold side (sucking electrons in).

There are some newer thermocouples made out of semiconductors which are much more efficient.

(Deleted comment)
Oh, because current PV cells are 12-18% efficient commercially, though in a lab, they can get close to a theoretical limit of 33.7%. This limit is tied to the top layer coating, which is a translucent ceramic of Indium-Tin-Oxide.

Newer technology can pick up around 45% using a gold mesh instead of an Indium-Tin-Oxide translucent ceramic layer. It also handles oblique exposure much better, but I'd really like to see some tech to increase that even further.

I'm thinking that a tubular mesh to make light pipes might help, sort of like the gold mesh in the new experimental stuff. Beyond that, something to translate less-favorable wavelengths may also help.

I don't see that sort of stuff for home use any time soon, but, for instance, if the space program needed higher efficiency, it might drive technologies that would end up in the commercial market in say, 10 years.

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