What is the biggest difference between Intrinsic and Extrinsic semiconductors?
The interviewer is testing your basic industry knowledge. The better you understand a topic, the more clearly you should be able to answer a question like this. A concise answer is best, but you can also use the opportunity to toss out scientific or industry-specific terms that demonstrate your knowledge, such as conductivity, purity, doping, or Fermi.
If you do not know the answer, make an educated guess. "I don't know" is never the right answer. Be transparent with the interviewer that you are unsure of the solution but offer any piece of knowledge that you may have.
"Intrinsic semiconductors are pure and do not include impurities. Extrinsic semiconductors contain variance in materials and are considered 'impure.' While impurities seem like they would be of negative quality, many pure sources are converted to extrinsic semiconductors through a process called 'doping.' Adding external materials improves the overall conductivity of the semiconductor."
"I am not certain of the difference between Intrinsic and Extrinsic semiconductors. I have worked with Extrinsic semiconductors, which I know contain some impurities, so perhaps Intrinsic semiconductors are made with only pure materials. I would love to learn more if you would give me the opportunity."
Remember to describe why one type of semiconductor would be used over the other type in your response if you know the difference between the two types. Interviewers value candidates that understand basic concepts and how to apply them properly.
Community answers are written by other candidates practicing this set. Reading how others frame the same question is one of the fastest ways to sharpen your own.
Anonymous Answer
Fermi level lies in between the conduction and valance band in which a number of electrons are equal to a number of holes. However, in the extrinsic semiconductor, Fermi energy lies towards the conduction band in N-type or towards the valance band in the p-type.
Amanda's Feedback
I appreciate the confidence and specificity of our answer. You can improve this answer by also sharing that the primary difference between intrinsic and extrinsic semiconductors is that intrinsic semiconductors are pure while extrinsic semiconductors typically contain trivalent or pentavalent impurities.
