Advertisements
Advertisements
Questions
How is a Zener diode fabricated?
Write two important considerations used while fabricating a Zener diode.
Solution 1
A Zener diode is fabricated by heavily doping both p and n sides of the junction
Solution 2
Two important considerations while fabricating a Zener diode are as follows:
(i) The Zener diode should be fabricated by heavily doping both p and n junctions.
(ii) Proper wafer-handling devices must be used to avoid contamination, which may affect the quality and stability of the diode.
APPEARS IN
RELATED QUESTIONS
With what considerations in view, a photodiode is fabricated? State its working with the help of a suitable diagram.
Even though the current in the forward bias is known to be more than in the reverse bias, yet the photodiode works in reverse bias. What is the reason?
Using the necessary circuit diagrams, show how the V-I characteristics of a p-n junction are obtained in
Forward biasing
How are these characteristics made use of in rectification?
Show the output waveforms (Y) for the following inputs A and B of (i) OR gate (ii) NAND gate ?
What happens to the width of depletion player of a p-n junction when it is (i) forward biased, (ii) reverse biased?
Answer the following question.
Explain the three processes involved in solar cell working.
What is the magnitude of the potential barrier across a Ge p-n junction?
A p-n photodiode is fabricated from a semiconductor with a band gap of 2.5 eV. lt can detect a signal of wavelength ______.
Which one of the following is not the advantage of LED?
Read the following paragraph and answer the questions.
|
LED is a heavily doped P-N junction which under forward bias emits spontaneous radiation. When it is forward-biased, due to recombination of holes and electrons at the junction, energy is released in the form of photons. In the case of Si and Ge diode, the energy released in recombination lies in the infrared region. LEDs that can emit red, yellow, orange, green and blue light are commercially available. The semiconductor used for fabrication of visible LEDs must at least have a band gap of 1.8 eV. The compound semiconductor Gallium Arsenide – Phosphide is used for making LEDs of different colours.
|
- Why are LEDs made of compound semiconductor and not of elemental semiconductors?
- What should be the order of bandgap of an LED, if it is required to emit light in the visible range?
- A student connects the blue coloured LED as shown in the figure. The LED did not glow when switch S is closed. Explain why?
OR
iii. Draw V-I characteristic of a p-n junction diode in
(i) forward bias and (ii) reverse bias
Briefly explain how emf is generated in a solar cell.
