The semiconductor used for fabrication o

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Target Exam

CUET

Subject

Physics

Chapter

Semiconductors and Electronic Devices

Question:

The semiconductor used for fabrication of visible LEDs must at least have a band gap of:

Options:

14 eV

1.8 eV

24 eV

3.0 eV

Correct Answer:

1.8 eV

Explanation:

The correct answer is Option (2) → 1.8 eV $n^{2}$

The energy of a visible light photons is typically in the range of 1.8 eV - 3.1 ev corresponding to about 700 nm (red) - 400 nm (violet).