Transient Double Injection in Semiconductors with Traps

Abstract

Deep traps can have important effects on the transient behavior of an electron-hole plasma injected into a long semiconductor. If the minority-carrier transit time is much shorter than all capture times (high voltage), trapping effects modify the trap-free transient after the first transit time by stretching out the transient and increasing the steady-state current. If the minority-carrier transit time is longer than the initial minority-carrier trapping time but shorter than all other capture times (intermediate voltage), trapping effects enter immediately. They reduce the velocity of the propagating plasma and cause the current to exhibit a long delay followed by a sharp rise. When the applied voltage is decreased further, the plasma velocity drops sharply toward zero because of recombination through the trapping centers. Properties for a typical bar of p-type InSb at liquid-nitrogen temperature are inserted in the appropriate formulas, and the results agree qualitatively with experimental data in the literature.