THE INFLUENCE OF A TRANSVERSE-EFFECTIVE-MASS DIFFERENCE ON THE CURRENT AT AN ABRUPT HETEROJUNCTION

The issue of momentum conservation, and its effect on tunneling, at an abrupt heterojunction interface between semiconductors of different t ransverse effective mass is considered. A thorough derivation is provi ded of the equations needed to calculate the electron tunnel current i n forward bias. Quantitative results are presented for the current in a variety of effective-mass-difference scenarios, including that of th e AlGaAs/GaAs case. The circumstances are identified in which the effe ctive-mass difference causes the current to differ significantly from the value computed when following the usual practice of assuming the e ffective masses are equal. (C) 1996 American Institute of Physics.