What is the maximum wave length of EM radiation required to move an electron from the valance band to conduction band of a semiconductor? [Given :Energy gap E _ g =1.98 10⁻¹⁹ ~J ; Planck's constant h=6.6 10⁻³⁴ Js ]

Step-by-step solution

The energy required to move an electron from the valence band to the conduction band is given by the energy gap E_ g . The relationship between the energy of a photon and its wavelength is given by E = hc . To find the maximum wavelength _ max required, we use the minimum energy E_ g : _ max = hc E_ g Given values are h = 6.6 10⁻³⁴ Js , E_ g = 1.98 10⁻¹⁹ J , and the speed of light c = 3 10⁸ m/s . Substituting these values into the equation: _ max = 6.6 10⁻³⁴ 3 10⁸ 1.98 10⁻¹⁹ _ max = 19.8 10⁻²⁶ 1.98 10⁻¹⁹ _ max = 10