Special features of the magnetodiode effect in multivalley semiconductors at low temperatures

The magnetodiode effect in a planar p-i-n structure was analyzed theoretically. This effect is accompanied by an intervalley redistribution of electrons in the vicinity of the structure's Hall surfaces at which the nonequilibrium charge carriers recombine. It is shown that consideration of the superposition of transverse charge-carrier fluxes caused by both the Lorentz force and the intervalley redistribution makes it possible to interpret the following special features of the current-voltage characteristics of Ge- and Si-based p-i-n structures at liquid-nitrogen and liquid-helium temperatures: (i) sublinear current-voltage characteristics observed at low temperatures both in the absence and in the presence of a magnetic field; and (ii) the emergence of a high polar magnetosensitivity at strong electric fields (at room temperature, the polar magnetosensitivity vanishes as a result of transition from weak to strong electric fields). (C) 2002 MAIK "Nauka / Interperiodica".