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Question
- Assertion (A): Putting the p-type semiconductor slab directly in physical contact with the n-type semiconductor slab cannot form the pn junction.
- Reason (R): The roughness at contact will be much more than inter atomic crystal spacing and continuous flow of charge carriers is not possible.
Options
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
If Assertion is true but Reason is false.
If both Assertion and Reason are false.
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Solution
If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
Explanation:
A pn junction cannot be formed by physically contacting a p-type semiconductor slab with an n-type semiconductor slab. The roughness upon contact does not match the inter-atomic crystal spacing of about 2-3 Å, resulting in a discontinuity. As a result, a continuous flow of charge carriers is impossible. So both the statement and the reason are correct, and the reason explains the assertion.
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