Auger effect provoked red to green color shift in the luminescence of highly excited Ga1-xAlxAs : Si

The existence region of {donor-acceptor1-acceptor2}-AUGER molecules is dete rmined in silicon-doped Ga1-xAlxAs by electron-beam excited luminescence me asurements at low temperature. The main peak position and luminescence inte nsity of the donor-acceptor recombination channel turns out to be affected in a characteristic manner on the existence of AUGER molecules at high exci tation 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 Ga0.2Al0.8A s, doped with 3.10(18) cm(-3) silicon atoms. Sample excitation is carried o ut at 77 K by means of a focused electron beam inside a cryostate. Experime ntal results are analyzed by use of a set of rate equations, incorporating a particular AUGER process. Good agreement between theoretical and experime ntal results is established.