Question

A p-n photodiode is made of a material with a band gap of 2 eV. The minimum frequency of the radiation that can be absorbed by the material is nearly:-

a) 20 x 1014 Hz
b) 10 x 1014 Hz
c) 5 x 1014 Hz
d) 1 x 1014 Hz

Answer 1

Answer:

c) 5x10^14

Explanation:

Ф= 2eV

Ф=hυ

⇒υ=Ф/h

⇒υ=2x1.6x10^-19/6.63x10^-34

⇒υ=5x10^14 Hz

Answer 2

E = 2.0 eV = 2 × 1.6 × 10⁻¹⁹ J

We know that, E = hν

.·. ν = E/h = (2 × 1.6 × 10⁻¹⁹) / (6.6 × 10⁻³⁴)

.·. ν ≈ 5 × 10¹⁴ Hz