Effects of a Magnetic Field on Double-Injection Negative Resistance in Long p+-π-n+ Structures

Abstract

Highly sensitive magnetic effects on the voltage-current characteristics in a long p+-π-n+ diode biased forwardly are analyzed. The solutions of this analysis are consistent with the following assumptions: The similar treatment for the Righi-Leduc effect, which is produced by the varied effect of the magnetic field on hot and cold carriers, is also applicable for the case where there is a density gradient in the sample. In addition, since the diffusion current and the effect of surface recombination are small enough to be neglected, the current flows through only the volume-recombination process. The major results are as follows: (1) Highly sensitive magnetic effect in ``double-injection regime'' mainly depends on the recombination process for the injected electrons which are minority carrier. This differs from the effect in ``Ohmic regime'' where majority carrier contributes to the current. (2) The threshold voltage, at which the negative resistance occurs, is strongly dependent on a ratio of the recombination density NR to the majority carrier density p0. (3) The current J in the double-injection regime beyond a minimum voltage follows a J ∝ V2+s law, where s is a function of the mobility ratio b, and it is given as s≈2(blog2−1).