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For semiconductors, the current (I) vs. voltage (V) relationship is as shown in the picture below.

enter image description here

As we increase the applied voltage, the electron-hole pairs generate increases too, so we see an almost linear increase in current.
Now if we consider metals, how will current behave if we increase voltage? Metals are full of electrons, so on increasing V, will it have any effect on I at all? I feel, the curve might be like this:

enter image description here

Is it correct?

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    $\begingroup$ Have you heard of Ohm’s law? $\endgroup$ – Farcher Apr 27 at 10:26
  • $\begingroup$ So by Ohm's law,will the I-V curve for metals will be a linear one like in semiconductors? $\endgroup$ – Shaona Bose Apr 27 at 10:28
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    $\begingroup$ Can you clarify what your first diagram shows? It looks like the graph for a PN junction rather than for a single semiconductor. $\endgroup$ – John Rennie Apr 27 at 11:36
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    $\begingroup$ @ShaonaBose no. The form of the VI curve for a diode is due to formation of a depletion layer at the junction. If you just have a chunk of semiconductor then it behaves like a regular ohmic conductor - well, that is until you reach field strengths strong enough to cause dielectric breakdown but that's far higher than normally used in circuits. $\endgroup$ – John Rennie Apr 27 at 12:52
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    $\begingroup$ @ShaonaBose yes $\endgroup$ – John Rennie Apr 27 at 13:58
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Ohm's law applies to metals.

In fact, Ohm developed the law through investigation of metals, not semiconductors, insulators, or other types of materials.

how will the I-V curve look like?

The I-V curve for a metallic conductor, or any other Ohmic conductor, is a straight line through the origin.

(In practical measurements, you might find the line is not perfectly straight, due to Joule heating and the material resistivity varying with temperature)

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  • $\begingroup$ But in the comments following my question, it says Ohm's law applies to semiconductors. I am confused again. Okay then how will the I-V curve look like? $\endgroup$ – Shaona Bose Apr 27 at 15:50
  • $\begingroup$ @ShaonaBose, Where did I say Ohm's law doesn't apply to semiconductors? $\endgroup$ – The Photon Apr 27 at 16:28
  • $\begingroup$ @ShaonaBose, in any case, you posted another question about semiconductors, so you should look there for answers addressing semiconductors. $\endgroup$ – The Photon Apr 27 at 16:32

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