Theory of impurity-band conduction in silicon inversion layers in high magnetic fields

Device Modeling at Cryogenic Temperatures: Effects of Incomplete Ionization

“…However, the rate of this decrease gets lower, i.e., below 50 K. We associate this with the mobility enhancement due to conduction in the impurity band, which is more influential at colder temperatures. However, at temperatures that are below 20 K, the mobility of the impurity band needs to be modified to take into account localization effects and the hopping processes, which will likely decrease the rise in current values at these temperatures [8], [17], [28]. Furthermore, similar bulk temperature characteristics can be obtained by using the dependence of bulk electron mobility on temperature that was suggested by [29], where the first term that was given by the power law can model the change in curvature at the lower temperatures and the second term can model the electron-phonon and impurity scatterings.…”

“…We also note that, to calculate current for the lowest temperatures of 20 and 25 K shown in Fig. 5(a), we accounted for the decrease in mobility due to the limitations of hopping processes for transport in the impurity band by adjusting the mobility using an exponential factor for tunneling [8], [28]. Furthermore, Fig.…”