Observation of abrupt first-order metal–insulator transition in Be-doped GaAs

An abrupt first-order metal–insulator transition (MIT) as a current jump is observed in Be-doped GaAs by inducing holes in a very low concentration of np≈5×1014cm-3 into the valence band by the electric field; this is anomalous. In a higher hole-doping concentration of np≈6×1016cm-3, the abrupt MIT is not observed at room temperature, but measured at a low temperature. The upper limit of the temperature allowing the MIT is deduced from experimental data to be approximately 440 K. The abrupt MIT is intrinsic and is compared with “breakdown” (an unsolved problem) produced by a high electric field in semiconductor devices.