INVESTIGATION OF THE MECHANISM OF FORMATION OF SLOW DOMAINS AND OF APPEARANCE OF NEGATIVE RESISTANCE IN GALLIUM ARSENIDE.

An investigation was made of the conditions under which low-frequency domain oscillations of the current appeared in samples of gallium arsenide doped with oxygen or chromium and having resistivities ranging from 0. 8 to 10**8 OMEGA multiplied by cm. It was established that the threshold field of the appearance of these oscillations was close to the threshold field of the Gunn oscillations. The assumption of the presence, near current contacts, of a layer with a resistivity higher than in the bulk of the sample made it possible to explain the nominal and real values of the threshold field and its dependence on the temperature of a sample and the illumination intensity. The results of a comprehensive investigation of the dynamics of formation and the kinetics of motion of domains were used to develop a theory and to suggest the most probable mechanism of the formation of slow domains, associated with the transfer of electrons from the (000) to the (100) valley followed by capture at impurity centers.