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प्रश्न
Answer the following question.
Why photodiodes are required to operate in reverse bias? Explain.
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उत्तर
The photodiode is reverse biased for operating in the photoconductive mode. As the photodiode is in reverse bias, the width of the depletion layer increases. This reduces the junction capacitance and thereby the response time. In effect, the reverse bias causes faster response times for the photodiode. The photocurrent is linearly proportional to the illuminance.
संबंधित प्रश्न
With reference to semiconductor devices, define a p-type semiconductor and a Zener diode.
The graph shown in the figure represents a plot of current versus voltage for a given semiconductor. Identify the region, if any, over which the semiconductor has a negative resistance.
A triode value operates at Vp = 225 V and Vg = −0.5 V.
The plate current remains unchanged if the plate voltage is increased to 250 V and the grid voltage is decreased to −2.5 V. Calculate the amplification factor.
In the circuit shown in figure, if the diode forward voltage drop is 0.3 V, the voltage difference between A and B is ______.
When an electric field is applied across a semiconductor ______.
- electrons move from lower energy level to higher energy level in the conduction band.
- electrons move from higher energy level to lower energy level in the conduction band.
- holes in the valence band move from higher energy level to lower energy level.
- holes in the valence band move from lower energy level to higher energy level.
Describe the following term briefly:
Breakdown voltage in reverse biasing
What is meant by forward biasing of a semiconductor diode?
Which practical effect is associated with forward bias?
Which practical effect is associated with reverse bias before breakdown?
Which voltage corresponds to a forward current of \[10\,\mathrm{mA}\]?
