Why can't we physically join p-type and n-type semiconductors directly to form a p-n junction? Why the depletion layer widens on doing so?
Asked by Aswin
| 14th Jan, 2016,
05:21: PM
Expert Answer:
A pn junction works if there is a continuous structure when joined.
If we physically join the two semiconductors, then there will always be very small microscopic gap or dicontinuity between the two because of roughness.
A p-type semiconductor has holes as majority carriers and the n-type semiconductor has electrons as majority. When a pn junction is formed, the holes from p and electrons from n move to the other type and hence, the width of the depletion layer widens.
Answered by Romal Bhansali
| 15th Jan, 2016,
12:07: PM
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