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A semiconductor of thickness 0.5μm is illuminated with monochromatic light of hϑ = 2eV, and the absorption coefficient of semiconductor α = −5 × 10−4cm−1. If the incident power is 10mW (Assume semiconductor has perfect quantum efficiency) then number of photons given from recombination events per second is photons/sec
  • a)
    2.87 × 1016
  • b)
    3.56 × 1016
  • c)
    4.98 × 1016
  • d)
    5.57 × 1016
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
A semiconductor of thickness 0.5μm is illuminated with monochromatic ...
I = I0e-αl
= 10-2 exp(-5 x 10-4 x 0.5 x 10-4)
= 0.82m W
Total energy absorbed = 10 - 0.82 = 9.18mW
Number of photons emitted
= 2.8687 x 1016 photons/sec
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Most Upvoted Answer
A semiconductor of thickness 0.5μm is illuminated with monochromatic ...
Number of Photons from Recombination Events per Second

Given data:
- Thickness of semiconductor (d) = 0.5 μm = 0.5 × 10^-4 cm
- Energy of monochromatic light (hϑ) = 2 eV
- Absorption coefficient of semiconductor (α) = -5 × 10^-4 cm^-1
- Incident power (P) = 10 mW

To find the number of photons given from recombination events per second, we can use the following formula:

Number of photons = (Power incident on the semiconductor / Energy per photon) × Quantum efficiency

Let's calculate each component step by step.

1. Power incident on the semiconductor (P_incident):
P_incident = P = 10 mW = 10 × 10^-3 W

2. Energy per photon (E_photon):
E_photon = hϑ = 2 eV × 1.6 × 10^-19 J/eV (converting eV to Joules)
E_photon = 3.2 × 10^-19 J

3. Quantum efficiency (η):
The semiconductor is assumed to have perfect quantum efficiency, which means all absorbed photons result in recombination events. Therefore, η = 1.

Now, we can substitute these values into the formula:

Number of photons = (P_incident / E_photon) × η

Number of photons = (10 × 10^-3 W) / (3.2 × 10^-19 J) × 1

Number of photons = (10 × 10^-3) / (3.2 × 10^-19) × 1 × 1 × 10^19

Number of photons = 3.125 × 10^16

Rounding off to two significant figures, we get:

Number of photons = 2.87 × 10^16 photons

Therefore, the correct answer is option 'A' - 2.87 × 10^16 photons.
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A semiconductor of thickness 0.5μm is illuminated with monochromatic light of hϑ = 2eV, and the absorption coefficient of semiconductor α = −5 × 10−4cm−1. If the incident power is 10mW (Assume semiconductor has perfect quantum efficiency) then number of photons given from recombination events per second is photons/seca)2.87 × 1016b)3.56 × 1016c)4.98 × 1016d)5.57 × 1016Correct answer is option 'A'. Can you explain this answer?
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A semiconductor of thickness 0.5μm is illuminated with monochromatic light of hϑ = 2eV, and the absorption coefficient of semiconductor α = −5 × 10−4cm−1. If the incident power is 10mW (Assume semiconductor has perfect quantum efficiency) then number of photons given from recombination events per second is photons/seca)2.87 × 1016b)3.56 × 1016c)4.98 × 1016d)5.57 × 1016Correct answer is option 'A'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about A semiconductor of thickness 0.5μm is illuminated with monochromatic light of hϑ = 2eV, and the absorption coefficient of semiconductor α = −5 × 10−4cm−1. If the incident power is 10mW (Assume semiconductor has perfect quantum efficiency) then number of photons given from recombination events per second is photons/seca)2.87 × 1016b)3.56 × 1016c)4.98 × 1016d)5.57 × 1016Correct answer is option 'A'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A semiconductor of thickness 0.5μm is illuminated with monochromatic light of hϑ = 2eV, and the absorption coefficient of semiconductor α = −5 × 10−4cm−1. If the incident power is 10mW (Assume semiconductor has perfect quantum efficiency) then number of photons given from recombination events per second is photons/seca)2.87 × 1016b)3.56 × 1016c)4.98 × 1016d)5.57 × 1016Correct answer is option 'A'. Can you explain this answer?.
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