A p-n photodiode is fabricated from a semicon | vedclass

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

Question

(C) The energy of a photon required to excite an electron across the band gap is given by $E_g = 2.5 \, eV$.For a photodiode to detect a signal,the en

Vedclass · Accepted Answer

$4000 \, \mathring{A}$

Vedclass · Answer

(C) The energy of a photon required to excite an electron across the band gap is given by $E_g = 2.5 \, eV$.For a photodiode to detect a signal,the energy of the incident photon $(E = \frac{hc}{\lambda})$ must be greater than or equal to the band gap energy $(E_g)$.Thus,$\frac{12400 \, eV \cdot \mathring{A}}{\lambda} \geq 2.5 \, eV$.Calculating the threshold wavelength $\lambda_{max} = \frac{12400}{2.5} \, \mathring{A} = 4960 \, \mathring{A}$.Any signal with a wavelength less than or equal to $4960 \, \mathring{A}$ can be detected.Among the given options,$4000 \, \mathring{A}$ is the only wavelength smaller than $4960 \, \mathring{A}$.

$A$ $p-n$ photodiode is fabricated from a semiconductor with a band gap of $2.5 \, eV$. It can detect a signal of wavelength:

Similar Questions

Which of the following statements is true about LEDs?

Which one of the following symbols represents a photodiode?

The laptop PCs,modern electronic watches,and calculators use the following for display:

The $I-V$ characteristics for a junction diode are shown. The device is

Why is the $I-V$ characteristic of a solar cell drawn in the fourth quadrant of the coordinate system?

Vedclass Test Series

Exam Paper Generator

Online Exam Module