Observation of an anomalously large blueshift of apparent donor–acceptor pair transition peak in compensation-doped quantum wells

Abstract
We have observed an anomalously large blueshift of the apparent donor–acceptor pair transition peak as the laser intensity increases in compensation-doped coupled quantum wells. The mechanism for the blueshift is the change of the Coulomb interaction energy between the recombined donors and acceptors due to the decrease in their separation as the laser intensity increases. The blueshift is accompanied by the saturation of the relative donor–acceptor pair transition peak intensity due to filling of the impurity states.