A semiconductor is doped with acceptor impurities with density NA=1019cm−3. The impurity level is at Eg/5 above Ev. Eg=20kT, and Ef=5kT above Ev (note that T, the temperature, is not necessarily room temperature). The effective masses are: m∗n=0.12m0 and m∗p=m0.
Ei=11.6kT above Ev
What fraction of the acceptors are ionized?