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Question
Answer the following giving reasons:
A p-n junction diode is damaged by a strong current.
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Solution
A strong current damages a p-n junction diode because it increases the semiconductor's temperature as more power passes through it and some of that energy is converted to heat. The semiconductor then conducts more current as the temperature rises a little further, which raises the temperature even further. Higher temperature results in more current, which increases the temperature. In what is referred to as a thermal runaway, this cycle keeps repeating. The semiconductor (p-n junction) is ultimately destroyed.
RELATED QUESTIONS
With reference to a semiconductor diode, what is meant by:
(i) Forward bias
(ii) Reverse bias
(iii) Depletion region
Basic materials used in the present solid state electronic devices like diode, transistor, ICs, etc are ______.
Diffusion in a p-n junction is due to ______.
The expected energy of the electron at absolute zero is called:-
Consider an npn transistor with its base-emitter junction forward biased and collector base junction reverse biased. Which of the following statements are true?
- Electrons crossover from emitter to collector.
- Holes move from base to collector.
- Electrons move from emitter to base.
- Electrons from emitter move out of base without going to the collector.
In the depletion region of a diode ______.
- there are no mobile charges.
- equal number of holes and electrons exist, making the region neutral.
- recombination of holes and electrons has taken place.
- immobile charged ions exist.
Can the potential barrier across a p-n junction be measured by simply connecting a voltmeter across the junction?
Draw a labelled characteristic curve (l-V graph) for a semiconductor diode during forward bias.
What opposes further diffusion in the depletion layer?
What happens to reverse current at the breakdown voltage?
