In a photodiode, the conductivity increases when the material is exposed to light. It is found that conductivity changes only if the wavelength is less than 600   n m . What is the bandgap?

Step-by-step solution

Given, The maximum wavelength of light, which increases the conductivity, λ = 600   n m Hence the energy of this photon must be equal to band gap ( E g ) . ∴   E g = h c λ = 6.6 × 10 - 34 × 3 × 10 8 600 × 10 - 9   J = 6.6 × 3 × 10 - 17 600 × 1.6 × 10 - 19   e V = 2 . 06   e V