Using deep-level transient spectroscopy and capacitance-voltage measurements, the effect of electric fields upon ionization of the S-related DX center was investigated for n-In1−xGaxP layers (x = 0.65) grown by vapor-phase epitaxy. It was shown that, upon increasing the field strength from 1.3 x 104 to 1.9 x 105V/cm, the activation energy of the center decreased from ~0.38 to ~0.26eV, and the ionization process was governed by multiphonon tunnelling. From the estimated tunnelling time of the defect, it was concluded that the DX center corresponded to a model of large lattice relaxation.

Ionization of the Sulfur-Related DX Center in In1−xGaxP in an Electric Field. Y.K.Krutogolov: Semiconductors, 2008, 42[2], 173-8