Photoionization cross section of the DX center in Si-doped AlxGa1-xAs

We report measurements of the photoionization cross section for the DX center in Si-doped AlxGa1-xAs. The temperature dependence of the photoionization cross section for the Si DX center is reported for the first time. Data have been measured in both direct- and indirect-gap material and over a much wider temperature range than was possible for the Te DX center, thus providing a more stringent test of any model than the earlier data. The results agree well with the large-lattice-relaxation model proposed by Lang et al. © 1987 The American Physical Society.