High temperature Superconductors and solar panels

Discussion in 'General Science & Technology' started by ajanta, May 14, 2016.

1. ajantaRegistered Senior Member

Messages:
611
• Post edited for off-topic quotes without citations, links or non-original content indicators.
Low temperature p-type semiconductor:

[Moderator: QUOTE DELETED. How is this so hard? You cut-and-pasted the entire abstract to
D. D. Edwall, E. R. Gertner, and W. E. Tennant, “Variable temperature hall effect on $\textrm{p-Hg}_{1−x}\textrm{Cd}_{x}\textrm{Te}$ grown on CdTe and sapphire substrates by liquid phase epitaxyJournal of Electronic Materials, 14 (3) , pp 245–268 (1985)

[Moderator: Taken from the third paragraph of the History section of “High-temperature superconductivity” I have surrounded your copied material with quote indicators so people won't mistake it for your original writing.]

(from wiki) [Moderator: Wikipedia is huge, so specific citations are needed. Clearly marked links are better. Taken from the first paragraph of the Iron-based Superconductors section of “High-temperature superconductivity” I have again surrounded your copied material with quote indicators. ]

So can superconductor be donor as n-type to low temperature p-type semiconductor for solar panels of high efficiency on cold planet or natural satellites ? Thanks

Last edited by a moderator: May 17, 2016

3. Billy TUse Sugar Cane Alcohol car FuelValued Senior Member

Messages:
23,198
I don't think you undersatand why silicon based PV cell is limited to about 23% conversion efficiency (looking at our sun).

A photon with energy equal to the band gap can be converted with 100% efficiency. I. e. just lift an electron from the top of the populated conduction band accross the band gap to the bottom of the basically unpopulated valence band.

If the photon has more than that energy, the electron will be lifted into a higher state of the valance band, and rapidly drop down to the bottom. The excess energy it had over the band gap energy is converted into heat as it cascades down.

A photon with less than the band gap can not do anything useful. It just makes heat as it induces collision among electrons of the conduction band.

The solar spectrum of photon energies is not as well matched to the band gap as that of a cooler star .

I did not follow your discussion of various semi-conductors as I believe it is all irrelevant for PV cells, unless you are creating a slightly larger band gap better matched to our sun.

ajanta likes this.

5. ajantaRegistered Senior Member

Messages:
611
Haa...haa...! Yes, you are correct, I don't undersatand why silicon/others based PV cell is limited to about .....% conversion efficiency (looking at our sun). I knew that it's about band gap but not as well. Thanks for your important description.

So larger band gap(p-type) better matched to light with superconductor as n-type(if it is possible) can be better efficient PV cell at low temperature(matched) ?

Last edited: May 14, 2016