A p–n photodiode semiconductor has band gap 2.0 eV. What is the minimum light frequency it can absorb?
Options

Question

A p–n photodiode semiconductor has band gap 2.0 eV. What is the minimum light frequency it can absorb?

G1 Physics · Accepted Answer

Use hf_min = E_g. Convert E_g = 2.0 eV = 2 × 1.602 × 10⁻¹⁹ J = 3.204 × 10⁻¹⁹ J. Then f_min = 3.204 × 10⁻¹⁹/(6.626 × 10⁻³⁴) = 4.84 × 10¹⁴ Hz ≈ 5 × 10¹⁴ Hz. Final answer: Option B.