The energy of a photon (λ = 589 nm) 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
Photon energy E = hc/λ = 1240/589 ≈ 2.1 eV, which matches the band gap energy required to create a hole-electron pair.
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A p-n junction forms when p-type and n-type semiconductor regions meet, creating a depletion layer, barrier potential and rectifying action. The work covers forward and reverse bias, junction current, diode characteristics, and how a diode converts alternating current into pulsating direct current through half-wave and full-wave rectification.
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