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from the does-it-also-make-the-room-darker? dept.
Researchers at the University of Michigan ran a light emitting diode (LED) with electrodes reversed in order to cool another device mere nanometers away. The approach could lead to new solid-state cooling technology for future microprocessors, which will have so many transistors packed into a small space that current methods can’t remove heat quickly enough.
This could turn out to be important for future smartphones and other computers. With more computing power in smaller and smaller devices, removing the heat from the microprocessor is beginning to limit how much power can be squeezed into a given space.
https://www.rtoz.org/2019/02/18/running-an-led-in-reverse-could-cool-future-computers/
[How does this compare to a Peltier device?
--Ed.]
(Score: 2) by JoeMerchant on Tuesday February 19 2019, @10:58PM (1 child)
Unfortunately, free market commercial demands for cheap energy means that we'll all freeze to death with all this heat converted to electricity...
I think the "infrared photon converted directly to electricity" is missing something, somewhere - probably one of those laws of thermodynamics having to do with entropy...
🌻🌻 [google.com]
(Score: 3, Informative) by c0lo on Tuesday February 19 2019, @11:27PM
1. if you want to cool the junction faster than the heat diffusion, you can but you'll need to "evacuate" the electrons promoted (by IR absorption) into the conduction band before they recombine and give you the absorbed heat back. Which means you'll need to maintain the reverse polarity on the diode, and this doesn't energetically come for free. The good thing in this 'thermal pump' setup - you are going to produce the extra heat in some other place, where you may be able to dissipate easier.
2. if you think, a photoelectric element is doing the light to electrical energy conversion without applying a reverse potential (and IR is light). But in this case, the junction is highly doped and the produced electrons/holes move under the gradient of charge concentration by thermal diffusion. If you make the junction thin enough, more charge carriers will reach the collecting electrodes (and "find it easier to travel" to the opposite side of the junction using the external circuit) than they recombine and you will have an electric current. However, you can't use this arrangement to cool (i.e. extract energy) faster than thermal diffusion - because the thermal diffusion of charge carriers that is the very engine which powers the PV element.
Now, the consequence of the above: you need the junction to be "hotter" than the outside circuit, otherwise the PV element will never generate electrical power (will simply act as a resistor).
In both cases, the laws of entropy are already at work.
https://www.youtube.com/watch?v=aoFiw2jMy-0 https://soylentnews.org/~MichaelDavidCrawford