There is an inverse relationship between the energy and the wavelength of the photon as it is shown in the equation below,
E = hc / λ
where E is energy, h is Planck's constant equal to 6.626 x 10^-34 J/s, c is the speed of light equal to 3 x 10^8 m/s, and λ is wavelength. Calculating for wavelength,
λ = (6.626 x 10^-34 J/s)(3 x 10^8 m/s) / (3.20 x 10^-15 J)
λ = 6.2 x 10^-11 m