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MHT CET · Physics · Semiconductors

A \(p-n\) photodiode is made of a material with a band gap of \(2.0\) eV. The minimum frequency of the radiation that can be absorbed by the material is nearly

  1. A \(10 \times 10^{14} \mathrm{~Hz}\)
  2. B \(5 \times 10^{14} \mathrm{~Hz}\)
  3. C \(1 \times 10^{14} \mathrm{~Hz}\)
  4. D \(20 \times 10^{14} \mathrm{~Hz}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(5 \times 10^{14} \mathrm{~Hz}\)

Step-by-step Solution

Detailed explanation

\(p-n\) photodiode is a semiconductor diode that produces a significant current when illuminated. It is reversed biased but is operated below the breakdown voltage. Energy of radiation \(=\) band gap energy ie, \(h v=2.0 \mathrm{eV}\)
or \(v=\frac{2.0 \times 1.6 \times 10^{-19}}{6.6 \times 10^{-34}} \approx 5 \times 10^{14} \mathrm{~Hz}\)