Question

The energy band gap of GaAs is 1.4ev. calculate the optimum wavelength of the light for photovoltaic generation in a GaAs solar cell

Answer 1

Answer:

The wavelength is  $\lambda = 886 \ nm$

Explanation:

From the question we are told that

   The  energy band gap is  $E = 1.4 eV$

Generally the energy of  a single photon of light emitted for an electron jump in a GaAS solar cell is mathematically represented as

      $E = \frac{hc}{\lambda }$

Where  h is the Planck's  constant with values

     $h = 4.1357 * 10^{-15} eV$

and  c is  the speed of light with values  $c = 3*10^{8} \ m/s$

So  

     $\lambda = \frac{hc}{E}$

substituting values

    $\lambda = \frac{4.1357 *10^{-15} * 3.0 *10^{8}}{1.4}$

  $\lambda = 886 \ nm$