AUGER EFFECT PROVOKED RED TO GREEN COLOR SHIFT IN THE LUMINESCENCE OF HIGHLY EXCITED Ga1-xAlxAs:Si

Abstract

The existence region of {donor-acceptor1-acceptor2}-AUGER molecules is determined in silicon-doped Ga1-xAlxAs by electron-beam excited luminescence measurements at low temperature. The main peak position and luminescence intensity of the donor-acceptor recombination channel turns out to be affected in a characteristic manner on the existence of AUGER molecules at high excitation levels. A shift between two recombination channels can be provoked, which involves the donor-acceptor pair transition at 1.8 eV, and a free-to-bound transition at 2.1 eV. We discuss own luminescence data of Ga0 2Al0 8As , doped with 3·1018 cm-3 silicon atoms. Sample excitation is carried out at 77 K by means of a focused electron beam inside a cryostate. Experimental results are analyzed by use of a set of rate equations, incorporating a particular AUGER process. Good agreement between theoretical and experimental results is established.