Capacitance-voltage characterization at various temperatures, and emission and capture deep-level transient spectroscopy, were carried out on undoped n-type material. The results supported the suggestion that the EL6 defect arose from a center that was DX-like in nature. The evidence in question was the observation of an anomalous filling pulse-duration dependence of the peak intensities of 3 or 4 different EL6 sub-levels which were similar to that which had been found for the DX center in AlGaAs and had been attributed to charge redistribution. The capture transients also revealed large capture barriers (0.2 to 0.3eV) which were typical of a defect that was undergoing large lattice relaxation into a deep-lying state. The observations indicated that the EL6 defect center consisted of a center with 3 or 4 slightly different ground-state configurations; each of which formed as a result of some bond-breaking atomic displacement upon capturing a second electron at the defect site.

DX-like properties of the EL6 defect family in GaAs C.V.Reddy, Y.L.Luo, S.Fung, C.D.Beling: Physical Review B, 1998, 58[3], 1358-66