Question

If electromagnetic radiation with wavelength of 150nm falls on a silicon surface , what will be the kinetic energy of ejected electron?​

Answer 1

When electromagnetic radiation of a particular wavelength hits a material, the kinetic energy of the electron ejected is given by:

K = HC/λ - ϕ

For silicon, the work function, φ is about 4.70 eV. Thus, when radiation with a wavelength of 150 nm hits a silicon surface, the maximum kinetic energy of the electron that would be ejected is:

K = (6.625 x 10^-34 J • S) (299792458 m/s) / 150 x 10^-9 m

Multiplied by (1ev/1.60 x 10^-19 J)

Subtracted by 4.70 eV

K = 8.28 eV - 4.70 eV = 3.58 eV

Hope it helps!!