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 Al0.35Ga0.65As into their shallow donor state, as monitored by measuring the resulting persistent photoconductivity. The energy dependence of the photoconductivity closely follows the simultaneously detected X-ray fluorescence, indicating that photoexcitation of core holes is an efficient primary excitation step for the excitation of DX centers. However, there is no appreciable difference between the Ga and As K-edges, implying a non-local DX center excitation mechanism.