Study of a deep donor level in $n$-GaAs by electron transport data obtained under hydrostatic pressure

The experimental pressure dependences of the resistivity and Hall effect at hydrostatic pressures from atmospheric to 18 GPa in $n$-GaAs are quantitatively analyzed. In the pressure range 10 $\le P\le$ 18 GPa, a deep donor center is found. The position of its energy level relative to the conduction-band $\Gamma$ valley edge at atmospheric pressure and its relation to the arsenic vacancy are discussed.