Band Discontinuity at Al_xGa_1-xP/GaP Heterointerfaces Studied by Capacitance Measurements

Abstract

The band discontinuity at Al x Ga 1- x P/GaP heterointerfaces for varying Al content has been studied by capacitance-voltage measurements and self-consistent numerical analysis of the apparent carrier concentration profile by taking account of the true heterointerface position and donor deionization. By extrapolating the results for the Al x Ga 1- x P/GaP system, it is shown that the band lineup of the AlP/GaP heterojunction is of type II with a conduction-band discontinuity of 0.23 eV. Discussion is presented of comparison with the previously reported values.