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I am doing my project on energy gap of semiconductors. For that i have an doubt that what will happen to the energy gap of diode if it is exposed to magnetic field intensity? Is it possible to place diode circuit in the magnetic field? If yes what is the relationship between enrgy gap and magnetic field. How can it calculated?

Is the threshold voltage of diode related to the energy gap? Eg=e*Vg? Then how to find threshold voltage from iv characteristics of diode?

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  • $\begingroup$ Hi and welcome to the Physics SE! What are your thoughts? Please note that you are expected to have thoroughly searched for an answer before asking your question. And it's important to detail where you're stuck and why, in order to attract good answers. You can consider checking the advice on writing good questions. $\endgroup$
    – stafusa
    Commented Jan 26, 2018 at 19:13
  • $\begingroup$ Nothing will happen that one would notice at ordinary field strengths. There is research about magnetic semiconductors (stuff like manganese-doped GaAs), but that is about different effects. (And then there are semiconductor Hall sensors.) $\endgroup$
    – user137289
    Commented Jan 26, 2018 at 19:14
  • $\begingroup$ +1 Nice question about the influence of an external magnetic field on the atoms magnetic dipole moments. $\endgroup$
    – HolgerFiedler
    Commented Jan 26, 2018 at 19:54

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There is an effect called Landau quantization which quantizes the cyclotron orbits (and thus energy levels) of free charge carriers in magnetic fields. For ordinary physical conditions (magnetic field strength, room temperature), the effect of a magnetic field on the energy band gap of a typical semiconductor is probably negligible. This energy quantization leads to the de Haas-van Alphen and Shubnikov-de Haas effect which can be observed at very low temperatures and large magnetic fields. The latter appears at very low temperatures in semiconductor inversion layers found in field-effect transistors. Such a quantized inversion layer is also called a two-dimensional electron gas.

You will probably not see any effect due to a change in energy band structure by putting a semiconductor diode into a a magnetic field. A much stronger, but still small effect would be the magnetoresistance. The "threshold voltage" of a semiconductor diode is a poorly defined technical, unphysical concept. It will probably not show a visible change.

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