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Which diode (semiconductor material) has the lowest voltage in the direction of conductivity?

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I do not know of a diode with "a" voltage. Please specify what voltage You mean. –  Georg Mar 20 '11 at 22:02
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Maybe he means band gap? This question definitely needs clarification. –  Colin K Mar 20 '11 at 22:09
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Schottky, down to 0.1V –  BarsMonster Mar 20 '11 at 23:51
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Perhaps it should be rephrased as "Which diode (semicondutor material) has the lowest forward voltage drop." Then indeed, Schottky is the answer, but I'd like to see a longer explanation having to do with physics. –  Carl Brannen Mar 21 '11 at 4:22
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I have been confused and inarticulate at times. I am especially grateful to those with the patience to interpret my poor communication and correct my faulty assumptions. I think all the comments here are constructive, both the ones asking for clarification, and the ones suggesting rephrasing. –  Andrew Mar 21 '11 at 14:21

2 Answers 2

up vote 2 down vote accepted

In fact, Schottky Diodes

have the lowest forward voltages. This means, that this is not a question of band gap "voltage" (this is a energy difference originally!) but of technology. Second are Germanium point contact diodes with gold wires.

"Diodes" made from Galena maybe are very low too, but due to the wiggely properties I would not dare to write about the "impressions" I had some times for some seconds on a scope.

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EDIT
Georg's note make me see that is not an answer to the OP.
I leave the rest of the text only to make notice of a very promising new techonoly.
end EDIT

Superconducting Niobium Chip Smashes Silicon Power Consumption Standards A superconducting logic chip with a clock speed of 6 GHz beats silicon energy efficiency by two orders of magnitude

Ref: Ultra-Low-Power Superconductor Logic
Abstract:

We have developed a new superconducting digital technology, Reciprocal Quantum Logic, that uses AC power carried on a transmission line, which also serves as a clock. Using simple experiments we have demonstrated zero static power dissipation, thermally limited dynamic power dissipation, high clock stability, high operating margins and low BER. These features indicate that the technology is scalable to far more complex circuits at a significant level of integration. On the system level, Reciprocal Quantum Logic combines the high speed and low-power signal levels of Single-Flux- Quantum signals with the design methodology of CMOS, including low static power dissipation, low latency combinational logic, and efficient device count.

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I cannot see that diodes are used in that niobium technology. This is interesting, since superconducting logic was proposed several times since the 50ties, but where is the relation to forward voltages of diodes? –  Georg Mar 24 '11 at 15:33
    
@Georg you said it very well. I did not read the paper and presumed that it has to be based in normal gates based on transistors to achieve digital treatment, and less power usually means less voltage. Now, that I looked inside, I find emerging technology even more interesting. –  Helder Velez Mar 24 '11 at 18:26
    
Strange, I thought that superconducting logic should exclude normal semiconductor logic. I was very curious by Your answer until I saw what is behind. The priciple is the same as I know from 50ties. Called "Kryotron" then, afair –  Georg Mar 24 '11 at 18:31
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Here is the history: en.wikipedia.org/wiki/Cryotron –  Georg Mar 24 '11 at 18:50
    
It's OK, and thanks for link Cryotron. Semiconduction has nothing to do with superconducting. The Cryotron behaves as a transistor controlled by the current rather than voltage. The formulation of the abs "the design methodology of CMOS" plus "+ digital chip ... Is this the rest of the story? [Josephson_effect] (en.wikipedia.org/wiki/Josephson_effect) and [single electron transistor (superconducting and voltage controlled)] (en.wikipedia.org/wiki/Single-electron_transistor). Superconductor digital is very promising. –  Helder Velez Mar 25 '11 at 0:08

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