Characterization of Deep Levels in Si-Doped InxAl1-xAs Layers Grown by Molecular Beam Epitaxy

Abstract
Deep levels in Si-doped InxAl1-xAs layers grown by molecular beam epitaxy were systematically investigated, changing the alloy composition for the first time. Deep level traps were characterized by deep level transient spectroscopy (DLTS) measurements and photoluminescence (PL) measurements. Two kinds of deep electron traps, E1 and E2 were observed. Least squares fitting curves of all data on the E1 and E2 traps were almost parallel to the Γ-band edge. From the observed dependence of trap level position on the alloy composition as well as from the comparison between DLTS and PL results, observed traps seem to be not DX center like donors but normal deep donors associated with the Γ-band.