X-ray excitation of DX centers in Si-doped Al0.35Ga0.65As

We report on the use of X-rays to excite DX centers in Si doped Al0.35Ga0.6 5As into their shallow donor state, as monitored by measuring the resulting persistent photoconductivity. The energy dependence of the photoconductivi ty closely follows the simultaneously detected X-ray fluorescence, indicati ng that photoexcitation of core holes is an efficient primary excitation st ep for the excitation of DX centers. However, there is no appreciable diffe rence between the Ga and As K-edges, implying a non-local DX center excitat ion mechanism, (C) 2000 Elsevier Science B.V. All rights reserved.