Transient excitation behavior of a donor–acceptor–acceptor Auger molecule in a semiconductor host

Abstract.

Under the particular situation of highly doped and almost compensated semiconductors, a new kind of bound state happens at high external excitation levels, which is formed of a close donor–acceptor molecule and a neighboring second donor or acceptor. The de-excitation behavior of such a bound state resembles characteristics known from Auger transitions and for this reason it is called an Auger molecule. The existence region of Auger molecules is determined in silicon-doped Ga_{1− x} Al _x As by electron-beam excited luminescence measurements at low temperature. The main peak position and the luminescence intensity of the donor–acceptor recombination channel turn out to be affected in a characteristic manner by the existence of Auger molecules at high excitation levels. An analysis of corresponding rate coefficients for the reproduction of experimental results is also presented.