I have quite a bit confusion that as per the 14th chapter of the book "Physical Foundations of solid-state devices" by E.F. Schuber the Hall concentration dependence on temperature at high temperature has been depicted as n=n0exp(- Ei/kT) for free electrons as per dual band model i.e. for double ionization energy whereas the temperature dependence has been scripted as p=p0exp(- Ei/2kT) in the paper "Impurity band in p-type beta-FeSi2" at high temperature for hole as per the similar dual band model. If someone resolve this confusion out by suggesting correct suggestion then it would be helpful for me.

For your kind convenience I am attaching both the documents with this message. Kindly suggest a correct suggestion to demonstrate the temperature dependence of Hall concentration.