DX centers in Sn-doped Al_xGa_1-xAs grown by metalorganic vapor phase epitaxy at T≥850°C

It was recently inferred from low-temperature transport measurements that DX centers are not formed in Sn-doped AlGaAs grown by metalorganic vapor phase epitaxy at T≥850°C. Deep level transient spectroscopy measurements reported here show that DX centers are present in this material. The high conductivity measured at low temperature comes from parallel conduction in the underlying GaAs due to Sn diffusion during growth at high temperature.