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If a semiconductor photodiode can detect a photon with maximum wavelength of 400 nm, then its band gap energy is : Planck’s constant h = 6.63 × 10^-34 J.s. Speed of light c = 3 × 10^8 m/s

1. 3.1 eV
2. 1.1 eV
3. 2.0 eV
4. 1.5 eV

Correct answer: 3.1 eV

Solution

The energy of a photon is inversely related to its wavelength, calculated using the formula E = hc/λ. For a maximum wavelength of 400 nm, this results in a band gap energy of approximately 3.1 eV, confirming that option A is correct.

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