EFFECTS OF ELECTRON ELECTRON-SCATTERING ON IMPURITY RESISTIVITY

All important theories of impurity resistivity each give one of two results. These two results coincide for zero temperature but differ for higher temperatures. The electron-electron scattering does not give a direct contribution to the resistivity. However, it has an indirect effect. It affects the occupation numbers of the electron states and thereby modifies the impurity scattering. The two results that we have discussed are both obtained in the absence of explicit electron-electron scattering. The solution of the Boltzmann equation in absence of electron-electron scattering gives one of the two results. In the limit of strong electron-electron scattering the second result is obtained; strong electron-electron interaction leads to full thermalisation in the centre-of-mass system of the carriers. Thus the two results are the extreme limits of the results from the Boltzmann equation for varying strength of the electron-electron scattering. In the present work we make a realistic estimate of the electron-electron scattering-rate and calculate the Boltzmann result for doped GaAs.