The binding energy of an electron trapped to a sulfur double donor S+6 in Si was measured by Prof. Sah and his graduate students at Illinois in 1971 using the photo capacitance transient method they invented and found to be 613.26 meV.
Assume that the static dielectric constant Is valid for screening the As core charge by the valence electrons and Is given by ε1/ ε0 = 11.8.
What is the orbit radius of an electron trapped at the ground state? How many valence electrons are enclosed in the Bohr sphere or in the spherical volume enclosed by the trapped electron orbit? Is the assumption on the static dielectric constant reasonable and why?