Statement -I: A photodiode operates in revers | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) photodiode is a special purpose $p-n$ junction diode fabricated with a transparent window to allow light to fall on the diode. It is operated unde

Vedclass · Accepted Answer

Statement $-I$ is true,Statement $-II$ is true,Statement $-II$ is the correct explanation of Statement $-I$.

Vedclass · Answer

(A) photodiode is a special purpose $p-n$ junction diode fabricated with a transparent window to allow light to fall on the diode. It is operated under reverse bias. When the photodiode is illuminated with light (photons with energy $h
u > E_g$),additional electron-hole pairs are generated. In reverse bias,the current is primarily due to minority carriers. The fractional change in this small reverse current due to the photo-effect is significant and easily measurable. In contrast,the forward bias current is dominated by majority carriers,which are already present in large numbers. The fractional change due to the photo-effect in forward bias is very small and difficult to detect. Thus,both statements are true,and Statement $-II$ correctly explains why the photodiode is operated in reverse bias.

Statement $-I$: $A$ photodiode operates in reverse bias.
Statement $-II$: The fractional change due to the photo-effects on the minority carrier dominated reverse bias current is more easily measurable than the fractional change in the forward bias current.

Similar Questions

The semiconductor used for the fabrication of visible LEDs must at least have a band gap of (in $eV$)

$A$ $p-n$ junction photodiode is fabricated from a semiconductor with a band gap of $2.5 eV$. It can detect a signal of wavelength: (Given: Planck's constant $h = 6.6 \times 10^{-34} Js$,speed of light $c = 3 \times 10^8 m/s$,elementary charge $e = 1.6 \times 10^{-19} C$)

The $I-V$ characteristics of a photodiode for different illumination intensities $I_1, I_2, I_3$ and $I_4$ are shown in the figure. Which of the following represents the maximum intensity?

$A$ photodiode is a device:

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Statement $-I$: $A$ photodiode operates in reverse bias.Statement $-II$: The fractional change due to the photo-effects on the minority carrier dominated reverse bias current is more easily measurable than the fractional change in the forward bias current.