Influence of the nonequilibrium-carrier concentration on the Hall voltage in a $p$-type semiconductor

The dependence of the Hall voltage on the external electric field in a $p$-type semiconductor sample placed in a weak magnetic field is investigated. It is shown that the Hall voltage depends nonlinearly on the electric field in a sample whose thickness is comparable to the diffusion length and surface-recombination velocity is rather small. The Hall-voltage sign is opposite to that in a bulk sample in a certain range of electricfield strengths. The theoretical model describes well the experimental data for a $p$-type Ge sample.