Semiconductors acceptor site density

Doping a p-type semiconductor generates fixed acceptor sites with a density Na, and an equal number of mobile carriers with an opposite charge h+, whose distribution is controlled by the local value of the potential T>(x), following the Boltzmann function so that the mobile charge distribution is given by ... 

For a semiconductor, the density of acceptor sites in the conduction band is given by the following relationship ... 

Semiconductors are characterized by low carrier densities 10 -10 ° carriers cm and low mobilities, typically 10 to 1.0Vcm -sec. Semicondnctors display an increase in conductivity with increasing temperatnre as the resnlt of thermal excitation of electrons located either at the top of the valence band (intrinsic carriers) or from impnrity sites in the forbidden gap, or from the filling of low lying acceptor levels in the case of p-type materials. In many cases, the temperatnre dependence is of the Ahrrenins form... 

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