Conductivity of a photodiode starts changing only if the wavelength of incident light is less than 660 nm . The band gap of photodiode is found to be X 8 eV . The value of X is: (Given h = 6 . 6 × 10 - 34 J s , e = 1 . 6 × 10 - 19 C )

Step-by-step solution

Given: Threshold wavelength = 660 nm . Therefore, energy required(or band gap energy) E g = h c λ = 6 . 6 × 10 - 34 × 3 × 10 8 660 × 10 - 9 J = 6 . 6 × 10 - 34 × 3 × 10 8 660 × 10 - 9 × 1 . 6 × 10 - 19 eV = 15 8 eV So, X = 15 .