First direct observation of EL2-like defect levels in annealed LT-GaAS

Transient current study of low-temperature grown GaAs using an n-i-n structure

“…Jäger et al showed using photocurrent measurements that annealed LT-GaAs has a deep level with the first onset energy of 0.76 eV, which is the same as that for the well-known midgap donor, EL2. 6 It is reasonable to detect EL2 in this material because EL2 is generally believed to include an arsenic antisite. 7 However, several groups have reported different energy levels as a dominant electron trap in this material.…”

Ultrafast excitonic room temperature nonlinearity in neutron irradiated quantum wells

“…In the case of LTG semiconductor materials short carrier lifetime has also been attributed to the presence of EL2 defect. 29 Moreover, neutron irradiated GaAs exhibits the same EPR spectrum due to EL2 defect as LTG GaAs. 30 We conclude, therefore, that in both cases EL2 defect exhibits the unique property of efficient reduction of carrier lifetime without excessive broadening of the exciton absorption resonance.…”

Carrier Dynamics and Defects in GaAs and Related Photoconductors

“…Two models currently exist to explain these properties: the deep-level point-defect model [Jager 1993] and the buried Schottky-barrier model [Warren 1991]. In the deep-level point defect model, the point defects, which are partly compensated by deep acceptors, control the electrical and ultrafast optical properties by keeping the Fermi level at mid-gap, as is found in bulk, semi-insulating GaAs.…”