Photoionization cross section of theDXcenter in Si-dopedAlxGa1−xAs

Abstract

We report measurements of the photoionization cross section for the DX center in Si-doped ${\mathrm{Al}}_{\mathrm{x}}$ ${\mathrm{Ga}}_{1\mathrm{-}\mathrm{x}}$As. 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.