The thermal activation and photo-excitation energies of one and two electrons trapped to the double or 2-electron sulfur donor were measured by Sah and his graduate students in 1971 by observing the photo and dark capacitance transients in a sulfur doped silicon p/n junction diode.
They found that the activation energies are 613.26 meV and 302.0 meV. Draw the energy band and transition energy diagrams for one and two electrons trapped to a double sulfur donor center.