The energy of a photon (λ = 589nm) equals the band gap of a semiconducting material. The minimum energy required to create a hole-electron pair is:
Correct answer: B. 2.1 eV
- A. 4.2 eV
- B. 2.1 eV
- C. 1.2 eV
- D. 0.98 eV
Explanation
The energy of a photon can be calculated using the formula E = hc/λ, where h is Planck's constant (4.135667696 × 10-15 eV·s), c is the speed of light (3 × 108 m/s), and λ is the wavelength in meters. Converting 589 nm to meters (589 × 10-9 m), the calculation yields approximately 2.1 eV. Thus, the minimum energy required to create a hole-electron pair in the semiconductor is 2.1 eV. Options 4.2 eV, 1.2 eV, and 0.98 eV are incorrect as they do not match the calculated energy from the given wavelength.
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About Photons and the Particle Model of Light
The particle model treats light as photons with energy E equals hf and momentum related to wavelength. Questions involve the photoelectric effect, work function, threshold frequency, stopping potential and photon energy, while distinguishing particle behaviour from the wave description of interference and diffraction.
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