Strongly anisotropic electric-field enhancement of the thermal emission rate of electrons from EL3 and EL5 deep-level defects in n-type GaAs crystals was revealed using double-correlation deep-level transient spectroscopy. The results, which took account of both Poole–Frenkel and phonon-assisted tunnel effects, revealed a strong coupling of the defects to the lattice vibronic modes. The defect potential anisotropy of EL3 was consistent with the defect being an off-centre substitutional oxygen on an arsenic site.

Anisotropic Electric-Field-Enhanced Electron Emission from Deep-Level Defects in GaAs. T.Tsarova, T.Wosinski, A.Makosa, Z.Tkaczyk: Semiconductor Science and Technology, 2009, 24[10], 105021